SOLUTION: What is the width of a uniform expansion needed all around to double the area of a 10cm by 15cm rectangle
Algebra.Com
Question 459813: What is the width of a uniform expansion needed all around to double the area of a 10cm by 15cm rectangle
Answer by mananth(16946) (Show Source): You can put this solution on YOUR website!
Let x be the expansion on all sides.
length & width will increase by 2x
(10+2x)(15+2x)=300
150+20x+30x+4x^2=300
4x^2+50x+150=300
4x^2+50x-150=0
2x^2+25x-75=0
Find the roots of the equation by quadratic formula
a= 2 ,b= 25 ,c= -75
b^2-4ac= 625 - 600
b^2-4ac= 1225
=35
x1=(-25+ 35)/4
x1=2.5
x2=(-25 -35)/4
x2= -15
Ignore negative value
x=2.5 the expansion
RELATED QUESTIONS
What is the width of a uniform expansion needed all around to double the area of a 10 cm... (answered by josgarithmetic)
Tee-jay has a photo that measures 10cm by 15cm. He want to fix it to a mat, so that there (answered by josgarithmetic)
We want to pack a gift in the form of a parallelogram, its dimensions are 10cm, 15cm, and (answered by ikleyn)
A photograph measuring 10cm by 15cm is to be framed with a border of uniform width... (answered by josgarithmetic)
How wide a border of uniform width should be added to a rectangle that is 8 inches by 12... (answered by solver91311)
How wide a border of uniform width should be added to a rectangle that is 8 inches by 12... (answered by mananth)
How wide a border of uniform width should be added to a rectangle that is 8 ft by 12 ft... (answered by mananth)
What is the total amount of edging that would be required to cover all edges of a... (answered by ikleyn)
Matt makes a cardboard frame to go around the edges of an 8cm * 10cm photograph. The... (answered by edjones)