Answer:
Second option: 81y^4 - 16x^2, the difference of squares
Step-by-step explanation:
(9y^2-4x)(9y^2+4x) is a special product named difference of squares, then we can apply this formula:
(a-b)(a+b)=a^2-b^2, with a=9y^2 and b=4x, then:
(9y^2-4x)(9y^2+4x)=(9y^2)^2 - (4x)^2
(9y^2-4x)(9y^2+4x)=(9)^2 (y^2)^2 - (4)^2 (x)^2
(9y^2-4x)(9y^2+4x)=81y^(2*2) - 16x^2
(9y^2-4x)(9y^2+4x)=81y^4 - 16x^2
4.5(8 - x) + 36 = 102 - 2.5(3x + 24)
36 - 4.5x + 36 = 102 - 7.5x - 60
72 - 4.5x = 42 - 7.5x
-4.5x + 7.5x = 42 - 72
3x = - 30
x = -30/3
x = -10 <===
Hope this helps!
I think it would have to equal a fraction being -4/3
Answer:
20
Step-by-step explanation:
If each space has an area of 5, we just have to multiply by 4 since there are 4 spaces.
4(5)=20