I believe the correct answer would be C.
There's two ways to do this.
The first way:
Work out the amount of sugar needed to make one cake, and then multiply that by 7.
30 grams ÷ 4 cakes = 7.5 grams for 1 cake.
7.5 grams × 7 cakes = 52.5 grams for 7 cakes.
The second way:
Work out the ratio of sugar:cake by doing 7 ÷ 4, and then multiplying that value by 30.
7 cakes ÷ 4 cakes = 1.75
1.75 × 30 grams = 52.5 grams for 7 cakes.
Either way, the answer is 52.5 grams.
63 + 36...there is a common factor of 9
9(7 + 4) <== this is equivalent
63 + 36...there is a common factor of 3
3(21 + 12)...but this is not an answer choice...but it is equivalent
You should choose c because it makes the most sense out of all of them
-10 + a = 6a - 7a
Rearrange the left hand side
a - 10 = 6a - 7a
Simplify 6a - 7a
a - 10 = -a
Add a on both sides
2a - 10 = 0
Add 10 on both sides
2a = 10
Divide by 2 on both sides
a = 5