Abel saved 43 more nickels than dimes. After he spent 17 dimes he had twice as many nickels than dimes. How many coins did he have left?

180 coins

Explanation:

N = number of nickels (no nickels spent)

D = number of dimes initially saved

D' = number of dimes left after spending

1) N = D + 43

2) D' = D - 17

3) N = 2*D' = 2*(D - 17)

Set equations 1) and 3) equal to each other and solve for D:

D + 43 = 2*(D - 17)

D + 43 = 2*D - 34

D = 43 + 34 = 77

N = D + 43 = 77 + 43 = 120 nickels left

D' = D - 17 = 77 - 17 = 60 dimes left

Total coins left = 120 + 60 = 180 coins (I hope this is not too confusing for you)

2 equivalent expressions to represent the area of a rectangle and the top is n-3 and the side is 2

area of the rectangle = length * width

given length = n - 3

width = 2

replace it in the area

so area of the rectangle = (n-3) *2

= 2(n-3)

one of the expression is 2(n-3)

to get another expression we distribute 2 inside the parenthesis

2(n-3) is 2n - 6

so another expression is 2n - 6

two equivalent expression are

2(n - 3)   , 2n - 6