i think in order to do this you might need to use a graph first. that is the way i learned it in school.
there are several ways to go at this. here's one of them.
multiply the second equation by 9/9, then substitute for 9y from the first equation.
(9y)/(9z) = 7/5
(7x)/(9z) = 7/5
now, multiply by 9/7.
x/z = (9/7)(7/5) = (9·7)/(5·7)
x/z = 9/5
remember use pemdas! there are no parentheses or exponents so lets move onto the first part of the equation: multiplication and division. first, lets break the first part of the equation up into something easier using the distributive property. 28 * 12= (20 *12) + (8*12) you know that 20*12 is 240 and 8*12 is 96. add them and you get 336. then, lets solve the last part of the equation (the last part of pemdas is addition and subtraction). 336 plus 34 is 370. hope this !
5 kg= 5000 g.