Question 1073596
Let x=grams of alloy1 (15% gold, 10%lead)

And let y=grams of alloy2(20% gold, 30% lead)

Total of amount of gold:
0.15x+0.20y=82.5  Eq1

Total amount of lead:
0.10x+0.30y=65  Eq2

Sooooo
0.15x+0.20y=82.5
0.10x+0.30y=65

Multiply eq1 by 2 and eq2 by3 and we get:
0.30x+0.40y=165 eq1a
0.30x+0.90y=195 eq2a

subtract eq1a from eq2a and we get
0.50y=30
y=60 grams amount of alloy 1
substitute 60 gms for y in eq1a
0.30x+24=165
0.30x=141
x=470 grams amount of alloy 2
CK
total amount of gold:
60*0.20+470*0.15=
12+70.5=82.5gms---check
total amount of lead:
60*0.30+470*0.10=
18+47=65gms---check
Hope this helps---ptaylor