5 is subtracted from both sides of the equation. x + 5 = 15: x+5 (-5) = 15 (-5);
when you subtract 5 on the left side of the equal sign the +5 (-5) cancel each other out to equal 0; when you do something to one side of the equal sign you must do the same thing to the other side; so subtract 5 from 15, and you are left with x + 0 = 10
which is x = 10.
When solving for x, you want to end up with x all alone on one side of the equal sign. You have to subtract (or add) the total sum on the x side to both sides of the equal sign.
5 Additional Examples when solving for x:
x + 7 = 13: you have to subtract 7 from both sides of the equal sign
x + 7 (-7) = 13 (-7) so x = 6
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x + 2 + 4 = 20: you have to subtract 2 and 4 from both sides of the equal sign
x + 2 + 4 (- 2) (- 4) = 20 (-2) (-4), so x = 14
a shortcut would be to subtract 6 from both sides of the equal sign since 2+4=6
x + 2 + 4 (-6) = 20 (-6) so x = 14
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x - 3 = 18: you have to add 3 to both sides of the equal sign
x - 3 (+3) = 18 (+3) so x = 21
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x - 5 - 4 = 17: you have to add 5 and 4 to both sides of the equal sign
x - 5 - 4 (+5) (+4) = 17 (+5) (+4), so x = 26
a shortcut would be to add 9 to both sides of the equal sign since -4 - 5 = -9
x - 5 - 4 (+9) = 17 (+9) so x = 26
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x + 7 - 3 = 19: you have to subtract 7 and add 3 to both sides of the equal sign
x + 7 - 3 (-7) (+3) = 19 (-7) (+3) so x = 15
a shortcut would be to subtract 4 from both sides of the equal sign since 7 - 3 = 4
x + 7 - 3 (-4) = 19 (-4) so x = 15
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I hope this helps you understand. You do not have to use the parentheses when adding or subtracting on either side of the equal sign. I just used them to make it easier to read.
-40
To find the number that minus 15 percent equals 13,600, you can set up the equation: ( x - 0.15x = 13,600 ). This simplifies to ( 0.85x = 13,600 ). Solving for ( x ), you divide both sides by 0.85, giving ( x = \frac{13,600}{0.85} ), which equals 16,000. Thus, the number is 16,000.
If x + 51 equals 17, then x must be negative. (If we are going to add 51 to some number and only get 17, an number less than 51, then we had to start at a negative number for this to happen.) Let's work through this one.x + 51 = 17x = 17 - 51 (we subtracted 51 from both sides of the equation)x = -34 (we have arrived at the answer)
To express the statement "seven subtracted from a number is 15" mathematically, you can write it as ( x - 7 = 15 ), where ( x ) is the unknown number. To find ( x ), you add 7 to both sides of the equation, resulting in ( x = 15 + 7 ). Thus, ( x = 22 ). The number is 22.
5/12
The property is: If equals are subtracted from equals, the results are equal.
-40
To find the number that minus 15 percent equals 13,600, you can set up the equation: ( x - 0.15x = 13,600 ). This simplifies to ( 0.85x = 13,600 ). Solving for ( x ), you divide both sides by 0.85, giving ( x = \frac{13,600}{0.85} ), which equals 16,000. Thus, the number is 16,000.
Any number can be subtracted. To reduce the fraction, you need to divide. In this case, 2 can be taken out. 34/54 = 17/27
20
If you are solving for y, it is fine. If you are solving for x, divide both sides by x and the equation should be x = y/x
If x + 51 equals 17, then x must be negative. (If we are going to add 51 to some number and only get 17, an number less than 51, then we had to start at a negative number for this to happen.) Let's work through this one.x + 51 = 17x = 17 - 51 (we subtracted 51 from both sides of the equation)x = -34 (we have arrived at the answer)
from another wikianswers page: say that 'a' is rational, and that 'b' is irrational. assume that a + b equals a rational number, called c. so a + b = c subtract a from both sides. you get b = c - a. but c - a is a rational number subtracted from a rational number, which should equal another rational number. However, b is an irrational number in our equation, so our assumption that a + b equals a rational number must be wrong.
To express the statement "seven subtracted from a number is 15" mathematically, you can write it as ( x - 7 = 15 ), where ( x ) is the unknown number. To find ( x ), you add 7 to both sides of the equation, resulting in ( x = 15 + 7 ). Thus, ( x = 22 ). The number is 22.
5/12
It is called solving by elimination.
If we call the number that we're looking for "x", then we can translate the question like this:When 15 is subtracted from 7x, the result equals 2x + 10Or:7x - 15 = 2x + 10Then it's a simple matter of simplifying the equation. Group like terms on either side of the equal operator:7x - 2x = 10 + 15Then add them together:5x = 25And factor five out of both sides:x = 5Giving you the answer.