25, 65, and y make a right triangle. use a^2 + b^2 =c^2.
so...
y^2 + 25^2 = 65^2
y^2 + 625 = 4225
y^2 = 3600 take the square root of both sides
y=60
Answer:
Step-by-step explanation:
Area = 3.14r^2
Area = 3.14(5)^2
Area = 3.14(25)
Area = 78.5
D= # of dimes
q= # of quarters
QUANTITY EQUATION:
d + q= 64
COST EQUATION:
0.10d + 0.25q= $9.25
STEP 1:
multiply quantity equation by -0.10 to be able to eliminate the d term in step 2
(-0.10)(d + q)= (-0.10)(64)
-0.10d - 0.10q= -6.40
STEP 2:
add equation from step 1 to cost equation to eliminate the d term and solve for q
Add
0.10d + 0.25q= $9.25
-0.10d - 0.10q= -6.40
0.15q= 2.85
divide both sides by 0.15
q= 19 quarters
STEP 3:
substitute q value in step 2 into either original equation to find d value
d + q= 64
d + 19= 64
subtract 19 from both sides
d= 45 dimes
CHECK:
0.10d + 0.25q= $9.25
0.10(45) + 0.25(19)= 9.25
4.50 + 4.75= 9.25
9.25= 9.25
ANSWER: There are 45 dimes and 19 quarters.
Hope this helps! :)
UGH I think I did this before but I totally forgot how to do it. Give me a minute to do some research and remember because I'm about 79% sure I know how to do this!
