Question

Subtract

(a) 8xy from 19xy
(c) (x² - y2)from (2x²-3y2 +7)
Simplify combining like terms:
(a) 3x² - 5x+7; -38x² + 4x-3 and 11x² +7x+8
(b) ²x²y + 2x²y +5 and ²x²y - 3x²y - 11
Find the value of the expression:
25x² +9y² + 30xy when x = -8 and y = -10

Answer 1

Subtract

(a) 19xy - 8xy = 11xy

(b) (2x^2-3y^2+7) - (x^2-y^2)(2x2−3y2+7)−(x2−y2) = x^{2}+2y^{2} +7x2+2y2+7

Simplify by combining like terms:

(a) (3x^2-5x+7) + (-38x^2+4x-3)+(11x^2+7x+8)(3x2−5x+7)+(−38x2+4x−3)+(11x2+7x+8) = -26x^2+6x+12−26x2+6x+12

(b) (x^2y^2 + 2x^2y+5) + (x^2y^2-3x^2y-11)(x2y2+2x2y+5)+(x2y2−3x2y−11) = 2x^2y^2-x^2y-82x2y2−x2y−8

Find the value of the expression:

25x^2 + 9y^2+30xy25x2+9y2+30xy when x = -8 and y -10

= 25(-8)^2+9(-10)^2+30*-8*-1025(−8)2+9(−10)2+30∗−8∗−10

= 4900

Answer 2

Subtract

(a) 19xy - 8xy = 11xy

(b)
`(2x^2-3y^2+7) - (x^2-y^2)` =
`x^(2)+2y^(2) +7`

Simplify by combining like terms:

(a)
`(3x^2-5x+7) + (-38x^2+4x-3)+(11x^2+7x+8)` =
`-26x^2+6x+12`

(b)
`(x^2y^2 + 2x^2y+5) + (x^2y^2-3x^2y-11)` =
`2x^2y^2-x^2y-8`

Find the value of the expression:

`25x^2 + 9y^2+30xy` when x = -8 and y -10

=
`25(-8)^2+9(-10)^2+30*-8*-10`

= 4900