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
It is 90+90 = 180