Answer:
Step-by-step explanation:
689.50/98.50 = 7 trampolines they sold
x < (8x - 21)/15
⇔ 15x/15 < (8x - 21)/15
⇔ 15x < 8x - 21
⇔ 15x - 8x < -21
⇔ 7x < -21
⇔ x < -21/7
⇔ X < -3