Solve for x: 3x + 7 = 22

Linear equation solving: isolate the variable. Step 1: subtract 7 from both sides: 3x + 7 − 7 = 22 − 7, giving 3x = 15. Step 2: divide both sides by 3: 3x ÷ 3 = 15 ÷ 3, giving x = 5. Verify: 3(5) + 7 = 15 + 7 = 22 ✓. The two-step linear equation is the foundation of algebra. Strategy: undo operations in reverse order of operations — first reverse addition/subtraction, then reverse multiplication/division. Many ASVAB MK problems use this structure. Common errors: dividing before subtracting; sign errors; arithmetic errors. Always verify by substituting the answer back into the original equation. Linear equations in one variable always have exactly one solution unless the variable terms cancel.