So try to get the x term to one side by itself
add 21 to both siede
3x+28=5x
subtract 3 x from both sides
28=2x
divide 2
14=x
Answer:
The hidden variable is age.
Step-by-step explanation:
That does not prove that larger shoes cause more studying math or vice versa.
The children with larger shoes are most probably older so they would have done more years of studying than the younger ones.
The hidden variable is the age of the child.
Answer:
Substitute 3x - 5 for y in the second equation.
Step-by-step explanation:
Generally, to solve the system of linear equations of x and y, the first step would be trying to eliminate x (or y).
Then turn the system into the equation of only y (or x).
Next, try to solve for y (or x).
Then substitute the solved y (or x) into the original system to work out x (or y).
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3 options (1 addition, 2 subtractions) do not eliminate x or y (x and y still exist after manipulation).
=> Remaining option relating substitution would be a reasonable choice.
Answer: A.
Step-by-step explanation:
