T M - time that Maria drove;
49 * t C + 52 * t M = 191
t C + T M = 3.8 hours
t C = 3.8 - t M
49 * ( 3.8 - t M ) + 52 * t M = 191
186.2 - 49 t M + 52 t M = 191
3 t M = 191 - 186.2
3 t M = 4.8
t M = 4.8 : 3
t M = 1.6 hours
Answer:
Maria drove 1.6 hours.
Answer:
2:1 I think heheheheeh
Step-by-step explanation:
lol
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! :)
(12+7x)(12-7x)
Because the square root of 144 is 12 and for 49 is 7