This situation has two unknowns - the total number of half dollars and the total number of quarters. Because we have two unknowns, we will write a system of equations with two equations using the two unknowns.

h+q=31 is an equation representing the total number of coins
0.50h+0.25q=11 is an equation representing the total value in money based on the number of coin. 0.50 and 0.25 come from the value of a half dollar and quarter individually.

We write the first equation in terms of q by subtracting it across the equal sign to get h=31-q. We now substitute this for h in the second equation.

0.50(31-q)+0.25q=11

15.5-0.50q+0.25q=11

15.5-0.25q=11

After simplifying, we subtract 15.5 across and divide by the coefficient of q.

-0.25q=-4.5

q=4

We now know of the 31 coins that 4 are quarters.

3 0

3 years ago

SOLVE STEP BY STEP !!!! answer correctly please !! Will mark brainliest !!!!!!!!!!!!!!

Mnenie [13.5K]

Step-by-step explanation:

(3X-20)+(3X+5)=111(( SINCE 111 IS TOTAL ANGLE

6X-15=111

6X=126

X=21

EFG=3×21-20

=63-20=43

8 0

3 years ago

mihalych1998 [28]

Answer

Secured

Step-by-step explanation:

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4 0

2 years ago

Read 2 more answers

The area of a rectangle is 30 square root 3750 square inches, and the length is 3 square root 250 inches what is the width of th

Ann [662]

Answer:

$width=10\sqrt{15}\ in$

Step-by-step explanation:

-A rectangle's area is given by:

$A=lw\\\\l=length\\w=width$

Given A= $30\sqrt{3750}$ and $l=3\sqrt{250}$ , we substitute in the formula to solve for the width as follows:

$A=lw\\\\30\sqrt{3750}=3\sqrt{250}\times w\\\\w=\frac{30\sqrt{3750}}{3\sqrt{250}}\\\\w=10\frac{\sqrt{3750}}{\sqrt{250}}\\\\=10\times \sqrt{\frac{3750}{250}}\\\\=10\sqrt{15}\ in$

Hence , the rectangle's width is $10\sqrt{15}\ in$

6 0

2 years ago