Question

name: ____________________________ period: __ date: ____________
tic - tac - toe
directions: complete tic - tac - toe by solving three equations in a row. you may do 3 horizontally, vertically or diagonally. show all work.
$x - 13 = 20$ $21 = 3x$ $\frac{x}{5} = -2$
$7 + x = -12$ $x + 9 = -4$ $-8x = -72$
$\frac{x}{-3} = 14$ $11 = 6 + x$ $19 = -12 + x$

Explanation:

Step1: Solve $x-13=20$

Add 13 to both sides:
$x-13+13=20+13$
$x=33$

Step2: Solve $21=3x$

Divide by 3 on both sides:
$\frac{21}{3}=\frac{3x}{3}$
$x=7$

Step3: Solve $\frac{x}{5}=-2$

Multiply by 5 on both sides:
$\frac{x}{5} \times 5=-2 \times 5$
$x=-10$

Step4: Solve $7+x=-12$

Subtract 7 from both sides:
$7+x-7=-12-7$
$x=-19$

Step5: Solve $x+9=-4$

Subtract 9 from both sides:
$x+9-9=-4-9$
$x=-13$

Step6: Solve $-8x=-72$

Divide by -8 on both sides:
$\frac{-8x}{-8}=\frac{-72}{-8}$
$x=9$

Step7: Solve $\frac{x}{-3}=14$

Multiply by -3 on both sides:
$\frac{x}{-3} \times (-3)=14 \times (-3)$
$x=-42$

Step8: Solve $11=6+x$

Subtract 6 from both sides:
$11-6=6+x-6$
$x=5$

Step9: Solve $19=-12+x$

Add 12 to both sides:
$19+12=-12+x+12$
$x=31$

Answer:

Top row (left to right): $x=33$, $x=7$, $x=-10$
Middle row (left to right): $x=-19$, $x=-13$, $x=9$
Bottom row (left to right): $x=-42$, $x=5$, $x=31$

(Example completed row: Top horizontal row with solutions 33, 7, -10; any 3-in-a-row set of solved equations is valid per the tic-tac-toe rule)