Answer:
x = 12
y = 9
12 coins of dimes
9 coins of quartes
Step-by-step explanation:
x ---> coins of dimes
y ---> coins of quartes
x + y = 21
0.1x + 0.25y = 3.45 * 100
x + y = 21 L1
10x + 25y = 345 L2
x = 21 - y
Reemplace in L2
10(21 - y) + 25y = 345
210 - 10y + 25y = 345
15y = 345 - 210
15y = 135
y = 9
x = 21 - y
x = 21 - 9
x = 12
42=(2w-6)+(2w-6)+w+w
42=6w-12
54=6w
w=9
42=2l+18
24=2l
l=12
length= 12cm, width= 9cm
Your answer is c 11 hope that helped