(2j+7)(2j−7)
=(2j+7)(2j+−7)
=(2j)(2j)+(2j)(−7)+(7)(2j)+(7)(−7)
=4j2−14j+14j−49
=4j2−49
Answer:
Step-by-step explanation: -81
Answer:
h=6 feet
Step-by-step explanation:
Given: 1. The base of a rectangle is three feet longer than its height.
2.Are of the rectangle=54 square meters
Let us say the rectangle has height h and base(breadth) b.
Since, the base of the rectangle is three feet longer than the height, we have b=h+3.
Also, Area of the Rectangle= hb
therefore, 54=h(h+3)
54= h2+ 3h
h2+3h-54=0 (Subtract 54 from both the sides)
To find the value of h we have to solve the quadratic equation.
[We have the equation in the form ax2+bx+c=0, to factorise the equation-
Step1. Find two numbers such that their multiplication is equal to ac and their addition is equal to b.
Step2. Replace b with these numbers.
Step3. Simplify the equation]
So, h2+3h-54=0
h2+9h-6h-54=0
h(h+9)-6(h+9)=0
(h+9)(h-6)=0
Which gives-
h= -9 or h= 6
As h is the height of the rectangle, h can not be -9.
so h=6 feet
and b=h+3=9 feet
So the dimensions of the rectangle are 6 feet for the height and 9 feet for the base.
Answer:
36:)
Step-by-step explanation:
Answer:
First you will want to turn 15% into a decimal, then you will subtract the decimal from 50. Hope this helped
Step-by-step explanation:
