Answer:
The new dimensions are 5 m by 12 m.
Step-by-step explanation:
The new dimensions are 3+x m and 10+x m where x is the amount of increase. We have the following system:
A = 3 * 10 = 30 where A is the original area.
2A = (3 + x)(10+x) ( because A was doubled).
Substituting for A = 30 in the second equation:
(3 + x)(10 + x) = 60
30 + 13x + x^2 = 60
x^2 + 13x - 30 = 0
(x + 15)(x - 2) = 0
x = -15, 2, x must be positive so we ignore -15.
x = 2 = the increase in the dimensions.
The new dimensions are 3+2 and 10 + 2
= 5 and 12.
