body{margin:0;} noscript{z-index: 10000; position: fixed; display: block; height: 100%; width: 100%; background: #fff;} noscript .fa{font-size: 40px; display:block; color: #daa520;} noscript div{margin-top: 6%; padding-left: 20px; padding-right: 20px; text-align: center;} ! You must have JavaScript enabled to use this site.

Dashboard

McGraw Hill Integrated II, 2012 View details

5. Solving Quadratic Equations by Using the Quadratic Formula

Finish the assignment

Continue to next subchapter

Exercise 47 Page 138

Make sure you write all the terms on the left-hand side of the equation and simplify as much as possible before using the Quadratic Formula.

2.1, - 1.4

Practice makes perfect

We will use the Quadratic Formula to solve the given quadratic equation. ax^2+ bx+ c=0 ⇕ x=- b± sqrt(b^2-4 a c)/2 a Let's start by rewriting the equation so all of the terms are on the left-hand side and then simplify as much as possible.

2.3x^2 - 1.4x = 6.8

SubEqn

LHS-6.8=RHS-6.8

2.3x^2 - 1.4x - 6.8 = 0

MultEqn

LHS * 10=RHS* 10

23x^2 - 14x - 68 = 0

Now, we can identify the values of a, b, and c. 23x^2 - 14x - 68 = 0 ⇕ 23x^2+( - 14)x+( - 68)=0 We see that a= 23, b= - 14, and c= - 68. Let's substitute these values into the Quadratic Formula.

x=- b±sqrt(b^2-4ac)/2a

SubstituteValues

Substitute values

x=- ( -14)±sqrt(( - 14)^2-4( 23)( - 68))/2( 23)

▼

Solve for x and Simplify

NegNeg

- (- a)=a

x=14±sqrt((- 14)^2-4(23)(- 68))/2(23)

CalcPow

Calculate power

x=14±sqrt(196-4(23)(- 68))/2(23)