8x - 2x = 90 so 6x = 90 so x = 15
45x
Change all signs, from -7 + 8x + 41 = 90 to +7 - 8x - 41 = -90
The answer is No Solution, Assuming the problem is [ x2 = 8x - 90 ]: x2 = 8x - 90 [ or, 2x = 8x - 90 ] 10x = (-90) x = (-9) So, lets plug in "x". 2(-9) = 8(-9) - 90 (-18) = (-72) - 90 (-18) = (-162) And thus, there is no solution.
x2 - 2x + 55 = 90x2 - 2x - 35 = 0(x+5)(x-7) = 0x = -5, 7
Complementary angles add up to 90 degrees so if y = 8x-20 degrees then the complement of y is 90 - (8x - 20) = 110 - 8x degrees.
Since there is only an expression - not an equation - you can simplify it but there is nothing to work out or solve. -7 + 8x + 40 + 90 = 8x + 123
y2 - 5y + 2x - x2 - 120 is not a circle. It is a hyperbola rotated through 90 degrees.
90 + 90 + 60 = 240
4x + 3y + 2z = 34; 2x + 4y + 3z = 45; 3x + 2y + 4z = 47 First, eliminate terms in z from 2 of the equations, by muliplying first equation by 2 and subtracting third equation from the answer: 8x + 6y + 4z = 68, subtract leaving 5x + 4y = 21 (equation 4) Similarly multiply the first equation by 3 and the second by 2 giving 12x + 9y + 6z = 102 and 4x + 8y + 6z = 90 Subtract again and we have 8x + y = 12 or y = 12 - 8x Substitute this in equation 4 gives 5x + 4(12 -8x) = 21 Simplify: 5x + 48 - 32x = 21 = -27x = -27 so x = 1 y = 12 - 8x so y = 4 and in one of the original equations 4 + 12 + 2z = 34, ie 2z = 34 -16 so z =9 Check: 2x + 4y + 3z = 2 +16 + 27 = 45 and 3x + 2y + 4z = 3 + 8 + 36 = 47 QED!
390
Oh, dude, that's like basic math, right? So, if you're trying to figure out what number plus 90 equals 180, it's 90. Like, you just subtract 90 from 180 and you get 90. Easy peasy lemon squeezy.