This is just a matter of substitution. The original problems tells you what x is, x = -2. And your equation is y = -7x + 2. So everywhere you see x, you need to substitute it with -2. Then you can carry out the operation and solve for y. So, let's begin!
y = -7x + 2
Substitute x.
y = -7(-2) + 2
x is being multiplied by -7, so that is what you will do with -2. Now simplify.
y = 14 + 2
Multiplying two negatives numbers, give you a what? A POSITIVE!
y = 16
Always check your work.
16 = -7(-2) + 2
16 = 14 + 2
16 = 16
YAY!! YIPPEE!!
(2, 1)
7x+3y where x=2 and y=9 can be written as (7*2)+(3*9) which can be simplified to (14)+(27), from there it's basic addition.
If: y = 3x+4 and y = 2-7x Then: 3x+4 = 2-7x So: 3x+7x = 2-4 => 10x = -2 => x = -1/5 By substitution: y = 17/5 Solution: x = -1/5 and y = 17/5
It is an up parabola.
You can get it to vertex form by completing the square: y = x2 + 7x + 4 ∴ y = x2 + 7x + (7/2)2 - (7/2)2 + 4 ∴ y = (x + 7/2)2 - 49/4 + 16/4 ∴ y = (x + 7/2)2 - 33/4
7x + y = 8 Subtract 7x from each side of the equation: y = -7x + 8
7x + y = 4y = 4 - 7x
7x+y=6
7x + 5y 7(3) + 5(2) 21 + 10 = 31
(2, 1)
7x + y + z = 6 7x + y + 4z = 9 y + x = 6 Take the first two statements and subtract them. 7x + y + z = 6 7x + y + 4z = 9 _____________ 0 + 0 - 3z = -3 Therefore: z = 1 Then you are left with: 7x + y + 1 = 6 7x + y + 4 = 9 which is impossible, so this is an impossible equation.
The Y intercept of y=7x+10 is 10.
7x+3y where x=2 and y=9 can be written as (7*2)+(3*9) which can be simplified to (14)+(27), from there it's basic addition.
7x + y + 3 = y7x + 3 = 07x = -3x = -3/7
If: y = 3x+4 and y = 2-7x Then: 3x+4 = 2-7x So: 3x+7x = 2-4 => 10x = -2 => x = -1/5 By substitution: y = 17/5 Solution: x = -1/5 and y = 17/5
If x=2, then 7x = 14 and if y=5 then 4y=20.
It is an up parabola.