Group and factor
undistribute then undistribute again
remember
ab+ac=a(b+c)
this is important
6d^4+4d^3-6d^2-4d
undistribute 2d
2d(3d^3+2d^2-3d-2)
group insides
2d[(3d^3+2d^2)+(-3d-2)]
undistribute
2d[(d^2)(3d+2)+(-1)(3d+2)]
undistribute the (3d+2) part
(2d)(d^2-1)(3d+2)
factor that difference of 2 perfect squares
(2d)(d-1)(d+1)(3d+2)
77.
group
(45z^3+20z^2)+(9z+4)
factor
(5z^2)(9z+4)+(1)(9z+4)
undistribuet (9z+4)
(5z^2+1)(9z+4)
x + y = 52
x = y - 18
Adding,
2x + y = 52 + y - 18
2x = 34
x = 17
y = x + 18 = 35
Check: x+y = 17+35 = 52, good
Answer: 17 and 35
B) Commutative property of Multiplication
Hope this helps!
She got 215....but if she would have gotten 10 more, she would have scored 60% of the total marks......so if she got (215 + 10) = 225 she would have scored 60% of the total marks...
so 60% of the total marks = 225
0.60x = 225
x = 225/0.60
x = 375 <===