Step-by-step explanation:
If x is the mass of 30% copper alloy, and y is the mass of 65% copper alloy, then:
x + y = 80
0.30x + 0.65y = 0.51(80)
Solving the system of equations using substitution:
0.30x + 0.65(80 − x) = 0.51(80)
0.30x + 52 − 0.65x = 40.8
11.2 = 0.35x
x = 32
y = 80 − x
y = 48
The metalworker needs 32 kg of 30% copper alloy and 48 kg of 65% copper alloy.
First lets change the fractions so they have common denominators:
3/5 = 6/10
The bank was 1/10, after adding the pennies it was 6/10
6/10 - 1/10 = 5/10 = 1/2
This means 400 pennies filled 1/2 the piggy bank.
There are 2 halves (1/2) to a whole ( full piggy bank).
The piggy bank can hold 400 x 2 = 800 pennies.
Answer:
The answer should be: B
I think it's B because there are 2 cups of water (2c) and 7 bottles of water (7w) which costs $16 so that would be 2c +7w=16. Also for the other one, it's 3 cups (3c) and 8 bottles of water (8W) and the cost is $19 so that would be
3c + 8w =19
Step-by-step explanation: Hope this helps and gl :))
6 * 7 = 42 so then you take and divide
42/3 = 14
