If 7x + 4 = 25, then the value of x is _________.
If 7x + 4 = 25, then the value of x is 3.
Step 1: Start with the equation:
(7x + 4 = 25)
Step 2: Subtract 4 from both sides to remove the +4:
(7x + 4 - 4 = 25 - 4)
Step 3: Simplify:
(7x = 21)
Step 4: Divide both sides by 7 to get x alone:
(dfrac{7x}{7} = dfrac{21}{7})
Step 5: Simplify:
(x = 3)
Check: Put (x = 3) back into the original equation:
(7(3) + 4 = 21 + 4 = 25) ✓