Answer:
width = 2 cm
Step-by-step explanation:
are of rectangle is equal to length times width
x is the width, then length is 3x + 4
so x(3x + 4) = 20
3x^2 + 4x = 20
3x^2 + 4x - 20 = 0
The formula to solve a quadratic equation of the form ax^2 + bx + c = 0 is equal to x = [-b +/-√(b^2 - 4ac)]/2a
so a = 3
b = 4
c = -20
substitute in the formula
x = [-4 +/-√(4^2 - 4(3)(-20))]/2(3)
x = [-4 +/- √(16 + 240)]/6
x = [-4 +/- 16]/6
x1 = (-4 + 16)/6 = 2
x2 = (-4 - 16)/6 = -20/6
since the width can't be a negative number, x2 is not the right answer
so x = 2
7√2 = n
Divide by 2 on both sides.
Answer:
That's a bit hard. Hope you can solve it!
see the attached picture:
