Question

Solve the equation. Check your answer

Answer 1

Cross multiply.

20 * 5 = 100
so
m * 4 = 100

Solve for m:

m * 4 = 100

Divide by 4.

m = 100/4

So what's m?

Answer 2

25?

Answer 3

hello

Answer 4

Yup. (:

Answer 5

you should check your answer
\[ \frac{25}{20} \]
you can simplify this by dividing top and bottom by 5
what do you get?

Answer 6

dont u divide 100 from 4 which u get 25 right? Yes, but when you check it is always good to do it a different way than the way you found the answer in the first place.
Otherwise, you might do the same (dumb) mistake when checking...

Answer 7

ok so the answer is m=25
right but then i want to check it by dividing the top and bottom by 5?

Answer 8

i got 5/4

Answer 9

thanks everyone

Answer 10

btw, another way to do this is
\[ \frac{m}{20}= \frac{5}{4} \]
multiply both sides by 20 but don't do the calculation.. just write times 20
\[ \frac{m}{\cancel{20}} \cdot \cancel{20} = \frac{5}{4}\cdot \frac{20}{1} \]
notice that you can simplify first, by dividing top and bottom by 5
\[ m= \frac{5 \cdot \cancel{20}5}{\cancel{4}\cdot 1}\]
\[ m= 25\]

Answer 11

Yes the answer is m = 25.

You check dividing the numerator by the denominator in each fraction. If you get the same answer then they are equivalent.
\[\frac{ 25 }{ 20 } = 25 \div 20 = 1.25\]\[\frac{ 5}{ 4 } =5\div4 = 1.25\]