44.0k views
5 votes
-3/5x-7/20x+1/4x=-90

User Kmmbvnr
by
6.1k points

2 Answers

6 votes
900/7

Combine like terms
-12x-7x+5x= -1800
Divide both sides
-14x=-1800
X=900/7
User Tanmally
by
5.4k points
4 votes

Answer:x=−

3150

899

≈−0.285396825

Explanation:

315x−

20

7

+

4

1

=−90

Least common multiple of 20 and 4 is 20. Convert −

20

7

and

4

1

to fractions with denominator 20.

315x−

20

7

+

20

5

=−90

Since −

20

7

and

20

5

have the same denominator, add them by adding their numerators.

315x+

20

−7+5

=−90

Add −7 and 5 to get −2.

315x+

20

−2

=−90

Reduce the fraction

20

−2

to lowest terms by extracting and canceling out 2.

315x−

10

1

=−90

Add

10

1

to both sides.

315x=−90+

10

1

Convert −90 to fraction −

10

900

.

315x=−

10

900

+

10

1

Since −

10

900

and

10

1

have the same denominator, add them by adding their numerators.

315x=

10

−900+1

Add −900 and 1 to get −899.

315x=−

10

899

Divide both sides by 315.

x=

315

10

899

Express

315

10

899

as a single fraction.

x=

10×315

−899

Multiply 10 and 315 to get 3150.

x=

3150

−899

Fraction

3150

−899

can be rewritten as −

3150

899

by extracting the negative sign.

x=−

3150

899

User Kris Walker
by
6.2k points