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5x+20=3x+4

7x-4=3x+8

2x+6=x-9

User Semaj
by
4.3k points

2 Answers

6 votes

[MA]:

x = -8

x = 3

x = -15

The explanation:

5x + 20 = 3x + 4

5x = 20 - 20 = 3x + 4 - 20

subtract = subtract = 5x = 3x - 16

5x = 3x - 16

5x - 3x = 3x - 16 - 3x

7x - 4 = 3x + 8

7x - 4 + 4 = 3x + 8 + 4

7x = 3x + 12

7x = 3x + 12

7x - 3x = 3x + 12 - 3x

2x + 6 = x - 9

2x + 6-6 = x - 9-6

2x = x - 15

2x = x - 15

2x - x = x - 15 - x

x = - 15

User Jmzagorski
by
5.8k points
7 votes

Answer:

To evaluate an expression, first calculate the

powers, then multiply and divide in order from

left to right, and finally add and subtract in order

from left to right. Parentheses have preference.

example: 14 − 3

2

= 14 − 9 = 5

example: 2• 4 + 3•5 = 8 +15 = 23

example: 10 − 2 • 3

2

=10 − 2 • 9 =10 −18 = −8

example: (10 − 2) • 3

2

= 8•9 = 72

Problems 1-7: Find the value:

1. 2

3

= 5. 0

4

=

2. −2

4

= 6. (−2) 4

=

3. 4 + 2•5 = 7. 1

5

=

4. 3

2

− 2 • 3+1=

Problems 8-13: Find the value if a = −3, b = 2 ,

c = 0, d = 1, and e = −3:

8. a −e = 11. e

d

+

b

a

2d

e

=

9. e

2

+ (d − ab)c = 12. b

e

=

10. a −(bc − d) + e = 13. d

c

=

Explanation:

To evaluate an expression, first calculate the

powers, then multiply and divide in order from

left to right, and finally add and subtract in order

from left to right. Parentheses have preference.

example: 14 − 3

2

= 14 − 9 = 5

example: 2• 4 + 3•5 = 8 +15 = 23

example: 10 − 2 • 3

2

=10 − 2 • 9 =10 −18 = −8

example: (10 − 2) • 3

2

= 8•9 = 72

Problems 1-7: Find the value:

1. 2

3

= 5. 0

4

=

2. −2

4

= 6. (−2) 4

=

3. 4 + 2•5 = 7. 1

5

=

4. 3

2

− 2 • 3+1=

Problems 8-13: Find the value if a = −3, b = 2 ,

c = 0, d = 1, and e = −3:

8. a −e = 11. e

d

+

b

a

2d

e

=

9. e

2

+ (d − ab)c = 12. b

e

=

10. a −(bc − d) + e = 13. d

c

=

User Yunfan
by
5.3k points
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