Sally has $21.40 in dimes and quarters. There are 100 coins in all. How many of each coin does she have?

x = dimes

y = quarters

We also know:

Dimes: 0.10

Quarters: 0.25

100 = x + y

So, 0.10x + 0.25y = 100

And, y = 100 - x

Let’s use substitution:

0.10x + 0.25( 100 - x ) = 100

= 0.10x + 25 - 0.25x = 100

= 25 - 100 = 0.25x - 0.10x

= (-75) = 0.15x

x = (-75) divide by 0.15

x = (-500)

answer rather than having to add and subtract the measurements of the semi-circle, notice that the semicircle to the left of ad is actually identical in area to the blank semicircle-shaped space to the left of bc. so if we transferred the red semicircle into the blank space, we would end up with a square of side length 24 cm. the area of a square is s^2 = 24^2 = 676 cm^2.

u also answered this so i think u would know but i am here to

put in or use mine

28

step-by-step explanation:

because that's the answer