Need plese it's easy just im stuck

CROSS MULTIPLICATION my friend
Sorry accidentally pressed answer instead of space down
Cross multiplication is multiplying across the = sign by the denominator and numerator. For example, 10/5=3/x
So we multiply across the = sign, giving us that 10x=15
It is much easier to solve from there; divide by 10 on both sides and x=1.5

3/x=4/20
Same principle applies:
60=4x
÷ by 4 (the coefficient of x)
x=15

2/x=6/10
20=6x
x=20/6 - - > 10/3

8/x=4/11
88=4x
x=22

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.