David W. answered • 09/08/15
Tutor
4.7
(90)
Experienced Prof
If the frame retained the same aspect ratio, then this is a ratio problem. We may word it in several ways (some make it easier to solve). Ratios may be expressed as fractions.
Let x = new height
(1) Original width is to original height is as new width is to new height.
5.7 / 4.8 = 34.2 / x
(2) New height is to new width is as original height to original width
x / 34,2 = 4.8 / 5.7
These equations simply invert each fraction. Then there are:
(3) Original width to new width is as original height is to new height.
5.7 / 34,2 = 4.8 / x
(4) New height is to original height is as new width is to original width
x / 4.8 = 34.2 / 5.7
PLZ read these ratios several times using two pictures for the ratios to compare. Either "width" and "height" or else "old" and "new" are on each side of the equal sign -- don't try to change both!
That means that cross multiplying always allows us to solve the problem (pick any of the equations):
5.7x = (4.8)(34.2)
x = (4.8)(34.2)/(5.7)
x = 28.8 in
Note: Taking 34.2/5.7 = 6, you might find that the frame was enlarged 6 times the original width. So, 6 times the original height of 4.8 is 28.8. This is what we just did, but with an intermediate answer.
