Answer:
34 = 2A + 1B + 4C
35 = 3A + 2B+ 2C
49 = 5A + 3B+ 2C
Pairs the 1st and 2nd equation, then eliminates C:
34 = 2A + 1B + 4C
35 = 3A + 2B + 2C
34 = 2A + 1B + 4C
-70 = -6A + -4B + -4C <---- multiplies 2nd equation by -2
Adds them together
-36 = -4A + -3B
36 = 4A + 3B <----- please label this equation ALPHA
Next, pairs the 2nd and 3rd equations, and eliminates C:
35 = 3A + 2B+ 2C
49 = 5A + 3B+ 2C
Subtracts the top equation from the bottom:
49-35 = 5a-3a + 3b-2b + 2c-2c
14 = 2a + b <--- please label this equation BETA
ALPHA: 36 = 4A + 3B
BETA: 14 = 2a + b
Solves the 2x2 system by substitution:
BETA: 14 - 2a = b <---- solves equation BETA for b
Substitutes into equation ALPHA:
36 = 4a + 3(14 - 2a)
36 = 4a + 42 - 6a
36 = 42 - 2a
-6 = -2a
a=3
b = 14 - 2a = 14 - 2(3) = 14 - 6 = 8
34 = 2a + b+ 4c
34 = 2(3)+ 8 + 4c
34 = 6+8 + 4c
34 = 14 + 4c
20 = 4c
c=5
1 pound of apples cost $3
1 pound of berries cost $8
1 pound of cherries cost $5
