number of 5c pieces --- x
number of 20c pieces --- 30-x
5x + 20(30-x) = 345
solve for x
i have 30 coins made up of 5c and 20c pieces that total $3.45. how many of each do i have?????
2 answers
number of 5c pieces --- x
number of 20c pieces --- 30-x
5x + 20(30-x) = 345
Expand
5x+600−20x=345
Simplify 5x+600−20x to −15x+600
−15x+600=345
Subtract 600 from both sides
−15x=345−600
Simplify 345−600 to −255
−15x=−255
Multiply both sides by −1
15x=255
Divide both sides by 15
x=25515
Simplify 255/15 to 17
x=17
number of 20c pieces --- 30-x
5x + 20(30-x) = 345
Expand
5x+600−20x=345
Simplify 5x+600−20x to −15x+600
−15x+600=345
Subtract 600 from both sides
−15x=345−600
Simplify 345−600 to −255
−15x=−255
Multiply both sides by −1
15x=255
Divide both sides by 15
x=25515
Simplify 255/15 to 17
x=17