Solution
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Represent the unknown terms
Let x represents the number of weeks
Let y represents the total number of test passed
STEP 2: Interpret the statements
For Rebecca
[tex]y=2x+12[/tex]For Marie
[tex]y=5x+3[/tex]STEP 2: Find the number of weeks they will pass the same amount of test.
This means that y will be equal to y
[tex]\begin{gathered} y=y \\ 2x+12=5x+3 \\ 2x-5x=3-12 \\ -3x=-9 \\ x=\frac{-9}{-3}=3\text{ weeks} \end{gathered}[/tex]Hence, they will both pass the same number of tests in 3 weeks
STEP 3: Find the amount of tests passed
For Rebecca
[tex]\begin{gathered} 2x+12 \\ x=3 \\ y=2(3)+12=6+12=18 \end{gathered}[/tex]For Marie
[tex]\begin{gathered} y=5x+3 \\ x=3 \\ y=5(3)+3=15+3=18 \end{gathered}[/tex]Both will pass 18 tests in 3 weeks
ANSWER:
In 3 weeks, the children will each have passed 18 tests.