Answer:
x = 15
Step-by-step explanation:
Given
3(2x + 5) = 3x + 4x ← collect like terms
3(2x + 5) = 7x ← distribute parenthesis on left side by 3
6x + 15 = 7x ( subtract 6x from both sides )
15 = x ⇒ x = 15
Susana swam the fastest
+0.1
Note that -4.5 + 4.4 = -0.1.
Adding 0.1 to -0.1 results in 0.
The unknown was +0.1.
