Solve the Equation: 2a(a-5) = (a+3)² + (a-3)²

Question

Find a a given that

2a(a5)=(a+3)2+(a3)2 2a(a-5)=(a+3)^2+(a-3)^2

Video Solution

Solution Steps

00:00 Find A
00:03 Open parentheses properly, multiply by each factor
00:17 Use shortened multiplication formulas to open parentheses
00:52 Calculate the squares and products
01:03 Reduce what we can
01:18 Collect like terms
01:28 Reduce what we can
01:33 Isolate A
01:40 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Expand both squared terms on the right side of the equation
  • Step 2: Simplify the terms and combine like terms
  • Step 3: Solve the simplified equation for a a

Let's now work through each step:

Step 1: Expand (a+3)2(a+3)^2 and (a3)2(a-3)^2.
We know:
(a+3)2=a2+6a+9(a+3)^2 = a^2 + 6a + 9
(a3)2=a26a+9(a-3)^2 = a^2 - 6a + 9

Step 2: Combine the expansions:
(a+3)2+(a3)2=(a2+6a+9)+(a26a+9)=2a2+18(a+3)^2 + (a-3)^2 = (a^2 + 6a + 9) + (a^2 - 6a + 9) = 2a^2 + 18.

Step 3: Now, equate to the left side and simplify:
The left side of the equation is given as 2a(a5)=2a210a2a(a-5) = 2a^2 - 10a.

Equating both sides:
2a210a=2a2+182a^2 - 10a = 2a^2 + 18

Subtract 2a22a^2 from both sides:
10a=18-10a = 18

Divide by 10-10 to solve for aa:
a=1810=1.8a = \frac{18}{-10} = -1.8

Therefore, the solution to the problem is a=1.8 a = -1.8 .

Answer

1.8 -1.8