# ACT Math 1.3 Intermediate Algebra

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ACT Math Intermediate Algebra Drill 1, Problem 3. Can you find the value of a in this expression?

ACT Math | Intermediate Algebra |

ACT Mathematics | Intermediate Algebra |

Algebra | Quadratic Equations Solve equations and inequalities in one variable Understand the relationship between zeros and factors of polynomials |

Foreign Language | Arabic Subtitled Chinese Subtitled Korean Subtitled Spanish Subtitled |

Intermediate Algebra | Quadratic equations (Quadratic Formula) Quadratic formula |

Language | English Language |

Product Type | ACT Math |

### Transcript

The quadratic equation looks like this:

We are drawing from a line of the equation "ax squared plus bx plus c."

...and we have to figure out what a, b and c are so we can plug them into the right places.

In this case, the 2 comes from here; it's A.

B is here, and it's 4.

And C is here, and it's negative 1.

Now we just plug in the numbers and this is what we get.

Now we just have to simplify. We get negative 4 plus or minus 4 squared which is 16....

...minus 4 times 2, then times negative 1...

... so it's plus 8... and we get negative 4 plus or minus 16 plus 8, or 24, here under

the square root symbol...

...all over 2 times 2, or 4.

Simplify one more time and we have...

Both A -- here... and B -- here.

Answer: D.