Answer:
The solution is b = -1.5
Explanation:
* To solve any proportion, we used the cross multiplication
Ex: If a/ b = c/d
- We will multiply the numerator of L.H.S with the denominator
of the R.H.S and equate it with the product of the denominator
of the L.H.S with the numerator of the R.H.S
∴ ad = bc
* Lets do that with our problem
∵
∴ 7 × 5 = 10 × (b + 5) ⇒ multiply
∴ 35 = 10(b) + (10)(5) ⇒ simplify
∴ 35 = 10b + 50 ⇒ subtract 50 from both sides
∴ -15 = 10b ⇒ divide both side by 10
∴ b = -1.5
* The solution is b = -1.5