Question

-Cat cantareste fiecare fruct?
mar+para+strugure=766g
mar+para=421g
para+strugure=531g

Answer 1

m+p+s = 766
m+p = 421 ⇒ 421 + s = 766 ⇒ s = 766 -421 ⇒ s = 345 g
p+s = 531 ⇒ p+345 = 531 ⇒ p = 531 - 345 ⇒ p = 186 g

m+p+s = 766
m + 186 + 345 = 766
m + 531 = 766
m = 766 - 531 = 235

m+p+s = 766
235 + 186 + 345 = 766

Answer 2

fie x-mar
      y-para
      z-strugure  
x+y+z=766
x+y=421
y+z=531

x=421-y
z=531-y

421-y+y+531-y=766
421+531-y=766
421-y=235
421=235+y
y=421-235
y=186
x=421-186=235
z=531-186=345