How to write Regina has 120 coins, all quarters and dimes. she has 10 more dimes than quarters. How many quarters and dimes does she have as an equation

So Regina has 120 coins=total

120=total

we will use q=number of quarters and d=number of dimes

120=d+q

she has 10 more dimes than quarters

d=q+10

so if we susitute this into the equation then we get

120 = (q+10) + q

add like terms

120=2q+10

subtract 10 from both sides

110=2q

divide both sides by 2

55=q

she has 55 quarters

subtitute into second equation

d=10+55

d=65

dimes=65

quarters=55