Friday

December 19, 2014

December 19, 2014

Posted by **Marian** on Tuesday, March 1, 2011 at 6:51am.

substitue x=7 into the equatiopn and explain why this shows that x=7 is the solution.

ok so i do this: if x=7 then the equation becomes

7^2-49=0

7^2=49

49-49=0

so x=7 is correct (is that explanation enough?)

now i have to write out a complete solution to the orginal equation - i thought i had already done that above, could someone help me out please!

- maths -
**Reiny**, Tuesday, March 1, 2011 at 8:56am**the solution:**

x^2 - 7x = 0

x(x-7) = 0

so x = 0 or x = 7

**the check:**

if x = 0

LS = 0^2 - 7(0) = 0

RS = 0

so x = 0

if x = 7

LS = 7^2 - 7(7) = 49-49 = 0

RS = 0

so x = 7

x = 0 or x = 7

(The correct way to verify a solution is to show for the given value that the original left side (LS) is equal to the original right side (RS) of the equation. )

**Answer this Question**

**Related Questions**

Maths - Properties of Planes - write a scalar equation, given it's vector ...

composite functions - f(x)=2x-4, g(x)=x squared + 5x What is F o G and Domain ...

algebra 2 - use a graphing calculator to graph the function y=x^2-3x+15. a. what...

Calculus - Find the limit of the function as x approaches -3 (2x^2 +4x+1) I'm ...

ALGEBRA - The table below shows two equations: Equation 1 |3x - 1| + 7 = 2 ...

Pre-algebra - Hi need help answering this question? In your own words, define ...

ALGEBRA - Bill is solving the equation 26x−21(6x+51)=40(11x+139). The ...

chemistry - How do you compare and contrast a chemical equation and an ionic ...

Maths - I have a summation formula for Fibonacci numbers. n (SUM)F(2i)=F(2n+1)-1...

Calculus - A three-sided fence is to be built next to a straight section of a ...