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I have no idea what I'm doing, please help

I have no idea what I'm doing, please help-example-1
User TomoJ
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Answer:

Master product = 36

I'll also add the solutions to the quadratic equation just in case you might need it later:

x = 1 and x = 9/4 (aka 2.25)

Explanation:

Currently, 4x^2 - 13x + 9 = 0 is in standard form, whose general equation is

ax^2 + bx + c. The master product is a set in solving by factoring, where we look for two numbers whose product equals a * c and add up to b.

The a * c is what we call the master product.

Thus, since 4 is a and 9 is c, the master product of our equation is 36 since 4 * 9 = 36

Do you have to solve for x or do you just need the master product. I'll find x anyhow, but if you just need the master product, just write that.

Steps for solving:

Step 1: Make sure trinomial is in standard form:

4x^2 - 13x + 9 = 0 is already in standard form, so this step is already given/complete.

Step 2: Find two terms whose product equals a*c and adds up to b:

In our quadratic, 4 is a, -13 is b, and 9 is c. We see that 4 * 9 = 36 and -4 * -9 = 36. Also, -4 + (-9) = -13, so our two numbers are -4 and -9.

Step 3: Replace bx term with two bx terms that use the numbers from:

Since our two numbers from step 2 are -4 and -9, we can replace -13x with -4x and -9x. Thus, our new quadratic is 4x^2 - 4x - 9x + 9

Step 4: Factor by grouping:

We can group 4x^2 -4x and -9x + 9

The greatest common factor of 4x^2 and -4x is 4x. Factoring it out gives us 4x(x - 1).

The greatest common factor of -9x and 9 is -9. Factoring it out gives us

-9(x - 1).

Step 5: Factor out common term and remaining term.

x - 1 is the common term, which leaves us with 4x - 9.

Thus, our equation is now (x - 1)(4x - 9) = 0.

Step 6: Set each term equal o 0 to solve for x:

Setting (x-1) equal to 0 and solving:

x - 1 = 0

x = 1

Setting 4x - 9 equal to 0 and solving:

4x - 9 = 0

4x = 9

x = 9/4

Thus, the solutions to the quadratic equation are x = 1 and x = 9/4.

Optional Step 7: Check validity of solutions by plugging in 1 for x and 9/4 for x in original equation in standard form:

Plugging in 1 for x in 4x^2 - 13x + 9 = 0:

4(1)^2 - 13(1) + 9 = 0

4(1) - 13 + 9 = 0

4 - 13 + 9 = 0

-9 + 9 = 0

0 = 0

Plugging in 9/4 for x in 4x^2 - 13 + 9 = 0:

4(9/4)^x - 13(9/4) + 9 = 0

4(81/16) - 117/4 + 9 = 0

81/4 - 117/4 + 9 = 0

-9 + 9 = 0

0 = 0

Thus, our solutions are correct

User StacyM
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