Answer: 
Step-by-step explanation:

Answer: 4
The given line has a slope of -1/4 as this is the number in front of the x. The general equation y = mx+b has m as the slope. So m = -1/4 is given
Flip the sign to get -1/4 turn into +1/4 or just 1/4
Then flip the fraction (aka reciprocal) to go from 1/4 to 4/1 and that simplifies to 4.
Multiplying the original slope (-1/4) and the perpendicular slope (4) will result in -1.
Hello,

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Salutations!
<span>The ratio of boys to girls in a school is 5:4. if there are 180 students, how many girls are there?
Let the number of girls and boys be 'x'.
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Add 5 and 4
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Now, multiply the ratios by 20.
Boys =
20 </span>× 5 = 100
Girls = 20 × 4 = 80.
There were 80 girls.
Hope I helped (:
Have a great day!