9. Jamie ha ahorrado $ 42 del dinero de su asignación para comprar libros. Si compra 5 libros a d dólares por libro, le quedarán 42 5d de su asignación. ¿Cuánto le queda si los libros cuestan $ 3.50 cada uno?

$24.50

Step-by-step explanation:

Jamie has saved $ 42 of his allowance money to buy books. If you buy 5 books at d dollars per book, you will have 42- 5d left of your allowance. How much is left if the books cost $ 3.50 each?

We have the equation

42 - 5d = Amount of Allowance left

d = 3.50

Hence:.42 - 5 × 3.50

= $42 - 17.5

= 24.5

x=17

step-by-step explanation:

solve 3x-24=x+10

then that makes it 2x=34 because you subtract an x from both sides to get rid of the one on the right, and then you add 24 to both sides to get rid of the 24 on the left

divide by both sides by 2 to get your answer so that you can get your answer