Let
R = Ralph's age
S = Sara's age
First statement is translated as:
S = 3R
Second statement is translated as:
S + 4 = 2(R + 4)
Use the first equation to be substituted into the second one in terms of R which is the one we are actually going to solve for Ralph's age.
Since S = 3R, then
3R + 4 = 2(R + 4)
3R + 4 = 2R + 8
3R - 2R = 8 - 4
R = 4 years old
In summary. The graph of each equation is a straight line, m is the gradient of the line and c is the y-intercept. Conversely, if a straight line has gradient m and y-intercept c it has equation y = mx + c.
It might be step 4 where it got dropped by step 3
Top right, it’s really easy just. Count the numbers
