Answer:
1.4in
Step-by-step explanation:
Length of Photo = 4in
Width of Photo = 3in
Unknown:
Value of X = ?
Solution:
Follow these steps:
Area of a rectangle = l x w
Since the photo is a rectangle; area of photo:
Area of photo = 4in x 3in = 12in²
For the area of the ad;
Length of ad = 4 + x
Width of ad = 3 + x
Given that,
the area of the photo = [tex]\frac{1}{2}[/tex] area of ad
12in² = [tex]\frac{1}{2}[/tex] area of ad
Area of ad = 24in²
Area of the ad;
(4 + x) (3 + x) = 24
12 + 4x + 3x + x² = 24
12 + 7x + x² = 24
x² + 7x = 24 - 12
x² + 7x = 12
x² + 7x - 12 = 0
Using the almighty formula where
a = 1, b = 7 and c = -12
x = [tex]\frac{-b (+/-) \sqrt{b^{2} } - 4ac}{2a}[/tex]
x = [tex]\frac{-7 + \sqrt[]{-7^{2} - 4x1x-12 } }{2x1}[/tex] or [tex]\frac{-7 - \sqrt[]{-7^{2} - 4x1x-12 } }{2x1}[/tex]
x = 1.4 or -8.4
therefore the answer is 1.4in
x is 1.4in
