-6+10c
I think, reorder the terms: -6+9c+c= -6+10c
What do you mean by that i mean yeah you can have as many as needed to subtract
Eq. 1 .10x + .25y = 9.45
Eq. 2 x + y = 60 rewrite as x = 60 - y and substitute into equation 1.
.10(60 - y) + .25y = 9.45
6 - .1y + .25y = 9.45
6 + .15y = 9.45
.15y = 3.45
y = 23
60 - 23 = 37
23 quarters
37 dimes
23* .25 = 5.75
37 * .1 = 3.70
5.75 + 3.70 =9.45
The expression (-4x + 9)^2 cannot be equal to (-4x)^2 + 9^2 because it is actually equal to the product of two factors (3 + 2sqrt x) (3- 2 sqrt x). One cannot use obviously distributive property. Hence the answer to this problem should be C. as she did not understand both perfect square trinomial and did not determine the product
