Math

(5x-8)(4x+3)=0
20x^2+15x-32x-24=0
20x^2-17x-24=0

then substitute until u get it to equal 0

First you can multiply (also known as FOIL) the equation out:

(5x-8)(4x+3) = 0
20x^2+15x-32x-24 = 0
20x^2-17x-24 = 0

Then you can use the quadratic equation to solve for x which is: (-b (+ or -) sqrt(b^2 - 4ac))/2a
or in english: the opposite of b plus or minus the square root of b squared minus 4ac all over 2a

20 = a, -17 = b, -24 = c

just plug that into your calculator and you should be good! (you can also google quadratic formula if you want it written clearly)

MAG2124427:

how do I solve the equation, (5x-8)(4x+3)=0

Hi MAG2124427,

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Think about this different equation
a * b = 0
What are the possible answers ?
You are multiplying 2 things and the answer is 0.
This will only happen if a or b or both are equal to 0.
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The same is true for you equation.
If (5x-8) * (4x+3) = 0 then either

5x-8 = 0 OR 4x+3=0
5x = 8 4x = -3

x = 8/5 = 1 and 3/5 or x = -3/4