Answer:
Step-by-step explanation:
you divide the two to the y, which is x=3/2y
then, you simplify the second equation to y, which is -3y= -4x+12
then, you substitute the x=3/2y into the second equation,
-3y = -6+12
-3y = 6
y = -2
Substitute the y into the first equation, x= 3/2y,
x = -3
Let dimes = d and quarters =q
D + q = 50
D= 50-q
0.10d + 0.25Q = 7.70
Replace d with 50-q:
0.10(50-q) + 0.25q = 7.70
Simplify:
5 -0.10q + 0.25q = 7.70
5 + 0.15q = 7.70
Subtract 5 from both sides:
0.15q = 2.70
Divide both sides by 0.15:
Q = 2.70 / 0.15
Q = 18
D = 50-18 = 32
There are 32 dimes and 18 quarters
Answer:
20 miles in an hour.
Step-by-step explanation:
4/5=0.8
16/0.8=x/1
cross product
0.8*x=16*1
0.8x=16
x=16/0.8
x=20
