Answer:
There are 19 dimes and 8 quarters
Step-by-step explanation: Q= Quarter and D=dimes
q+d= 27; q=.25 and d=.10;
.25q+.10d= $3.90
q= 27-d
.25(27-d)+.10d=3.90 >Distribute .25 through the parenthesis
= 6.75-.25d+.10d=3.90 >Combine like terms
= -.15d=3.90-6.75 >Subtract 6.75 from both sides of the equation
= -.15d=-2.85 >Subtract
= d=19 >Divide both sides by -.15
q= 27-d>>>>> q= 27-19
q= 8
