Q3. Solve each equation by factoring... [FREE SOLUTION]

91影视

Geometry

Ray C. Jurgensen, Richard G. Brown, John W. Jurgensen

$Math Studyset 91影视 Explanations$ Math

Student Edition 路 227 pages

ISBN: 9780395977279

Chapter 4: Q3. (page 163)

Solve each equation by factoring or by using the quadratic formula. The quadratic formula is:
If $a x^{2} + b x + c = 0$ , with $a 鈮� 0$ , then $x = \frac{鈭� b 卤 \sqrt{b^{2} 鈭� 4 a c}}{2 a}$ .
$y^{2} 鈭� 7 y 鈭� 18 = 0$

Short Answer

Expert verified

The values of $y$ are $y = 9$ and $y = 鈭� 2$ .

Step by step solution

Step 1. Understand the concept used.

If $a x^{2} + b x + c = 0$ , with $a 鈮� 0$ , then $x = \frac{鈭� b 卤 \sqrt{b^{2} 鈭� 4 a c}}{2 a}$ . Solving using factoring can be done by splitting the middle term of the equation and then making groups and equating them to zero.

Step 2. Substitute the values.

It is given that $y^{2} 鈭� 7 y 鈭� 18 = 0$ . Using quadratic formula $y = \frac{鈭� b 卤 \sqrt{b^{2} 鈭� 4 a c}}{2 a}$ , substitute 1 for $a, - 7$ for $b$ and $- 18$ for $c$ .

Put the values in the formula and get $y = \frac{鈭� (鈭� 7) 卤 \sqrt{{(鈭� 7)}^{2} 鈭� 4 脳 (1) 脳 (鈭� 18)}}{2 (1)}$ .

Step 3. Simplify for y.

Simplify the expression for $y$ .

$y = \frac{鈭� (鈭� 7) 卤 \sqrt{{(鈭� 7)}^{2} 鈭� 4 脳 (1) 脳 (鈭� 18)}}{2 (1)}$

$= \frac{7 卤 \sqrt{49 鈭� (鈭� 72)}}{2} = \frac{7 卤 \sqrt{121}}{2} = \frac{7 卤 11}{2}$

Therefore, either $y = \frac{7 + 11}{2} = \frac{18}{2}$ or $y = \frac{7 鈭� 11}{2} = \frac{鈭� 4}{2}$ that is., either $y = 9$ or $y = 鈭� 2$ .

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91影视

Solve each equation by factoring or by using the quadratic formula. The quadratic formula is:
If $a x^{2} + b x + c = 0$ , with $a 鈮� 0$ , then $x = \frac{鈭� b 卤 \sqrt{b^{2} 鈭� 4 a c}}{2 a}$ .
$y^{2} 鈭� 7 y 鈭� 18 = 0$

Short Answer

Step by step solution

Step 1. Understand the concept used.

Step 2. Substitute the values.

Step 3. Simplify for y.

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

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91影视

Solve each equation by factoring or by using the quadratic formula. The quadratic formula is:If ax2+bx+c=0, with a鈮�0, then x=鈭�b卤b2鈭�4ac2a.y2鈭�7y鈭�18=0

Short Answer

Step by step solution

Step 1. Understand the concept used.

Step 2. Substitute the values.

Step 3. Simplify for y.

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Math Textbooks

Applied Mathematics

Theoretical and Mathematical Physics

Discrete Mathematics

Logic and Functions

Decision Maths

Geometry

Study anywhere. Anytime. Across all devices.

Solve each equation by factoring or by using the quadratic formula. The quadratic formula is:
If $a x^{2} + b x + c = 0$ , with $a 鈮� 0$ , then $x = \frac{鈭� b 卤 \sqrt{b^{2} 鈭� 4 a c}}{2 a}$ .
$y^{2} 鈭� 7 y 鈭� 18 = 0$