Answer:
D
Step-by-step explanation:
<span>There are 53 dimes in Jonahs piggy bank. You must use algebra to solve for a variable X as follows:
x.10+(91-X).05=7.2
Solving through will yield X =53 which means 91 - 53 = 38.
53*.10 + 38*.05 = $7.20.
Other methods will also work, but this is the most straight forward.</span>
The answer is D. The last one
You can multiply both sides by a number that will get rid of the denominators. For ex. you can multiply the first equation by 12 because 4 and 3 both go into 12 evenly. MAKE SURE YOU MULTIPLY THE OTHER SIDE BY 12 AS WELL! Therefore, 12(x/4) - 12(y/3) = 12(1), or 3x - 4y = 12