Answer:
-5/2
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
x² - 81 ← is a difference of squares and factors in general as
a² - b² = (a + b)(a - b)
Here a = x and b = 9, thus
x² - 81 = (x + 9)(x - 9) → D
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! :)
A. I took a educated guess
R = A / tetha
70° × pi/180 = radian
radian = 1.222 rad
3 = A / 1.222
Arc = 3.7 meter
i am a mathematics teacher. if anything to ask please pm me
