Question 737686
Peas cost $y per kg and Beans cost $(y+2) per kg. $15 is spent on peas and $9 on beans. The total mass of the peas and the beans is 8 kg. Write an expression for both the peas and the beans to determine the mass of each. Steps Required.


Peas cost $y per kg 
amount spent = $15

Number of kg = 15/y

Beans cost $(y+2) per kg. 
amount spent = $9 
Number of kg = 9/(y+2)

 The total mass of the peas and the beans is 8 kg.


{{{15/y + 9/(y+2)= 8}}}



{{{(15(y+2)+9y)/(y(y+2)) =8}}}



(15y+30 +9y)= 8y(y+2)

24y+30 = 8y^2+16

8y^2-24y-14=0

/2
4y^2-12y-7=0

4y^2-14y+2y-7=0

2y(2y-7)+1(2y-7)=0

(2y-7)(2y+1)=0

2y=7  OR  2y=-1

ignore negative

2y=7
y=3.5 

now you can work out x