Answer:OK
Step-by-step explanation:
Let x be the score of the 3rd quiz,, then the average score will be:
(83+91+x)/3, which = (174+x)/3. but this average should be greater or equal to 85 and smaller or equal to 90:
85 ≤ (174+x)/3 ≤ 90
1st multiply all terms with 3 → 255 ≤(174+x) ≤ 270
2nd subtract 173 from all terms → 255-174 ≤174-174+x ≤270-174
81 ≤ x ≤ 96
Answer:
here
Step-by-step explanation:
I also send the graph
if you want to expand i can write that too
Answer:
x = (-7,7)
Step-by-step explanation:
1.add 5 on both side
2.divide each side of the equation by 2
3.take the square root of each side of the equation to solve for x
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! :)
