Each tweet would cost between 1 and 140 pennies you can write that as an inequality [1 ≤ x ≤ 140] Since you can't tweet 0 characters or above 140.
if you want to change it to pounds divide by 100.
A) 1 ≤ x ≤ 140
B) Each character costs a penny, you can't tweet less than 1 character or above 140.
Make a ratio and cross multiply
5(2x - 8) + 15 = -15
-15 -15 subtract 15 from each side
5(2x - 8) = -30
÷5 ÷5 divide both sides by 5
2x - 8 = -6
+8 +8 add 8 to each side
2x=2
÷2 ÷2 divide both sides by 3
x = 1
Checking:
5(2(1)-8) + 15 = -15
5(-6) + 15 = -15
-30 + 15 = -15
-15 = -15 Correct! x=1