original height was 5" and it was enlarged to 30"
find the ratio by dividing 30 by 5
30 / 5 = 6
so ratio would be 1/6 meaning for every 1 inch of the original the new one is 6 inches
now you need to multiply the original width by 6 to find the new width
7" x 6 = 42"
new width = 42"