If x = 4, what is the value of 3x + 7?
Substitute x = 4 into the expression: 3(4) + 7 = 12 + 7 = 19. Multiply before adding.
Why the other choices are wrong
- B 14 - 14 results from adding 3 + 4 + 7 instead of multiplying 3 by 4.
- C 21 - 21 is 3 times 7, which ignores the value of x.
- D 28 - 28 is 4 times 7, which drops the coefficient 3.