Answer:
12. Option b: 20 is the correct answer.
13. Option a: A rose costs $1 more than a daisy is the correct answer.
Step-by-step explanation:
12. Given that:
15x+10y=700 Eqn 1
x+y=60 Eqn 2
To find x, we will eliminate y be multiplying Eqn 2 by 10
10(x+y=60)
10x+10y=600 Eqn 3
Subtracting Eqn 3 from Eqn 2
(15x+10y)-(10x+10y)=700-600
15x+10y-10x-10y=100
5x=100
Dividing both sides by 5
Hence,
Option b: 20 is the correct answer.
13. Given that:
5x+4y=32 Eqn 1
x+6y=22 Eqn 2
Multiplying Eqn 2 by 5
5(x+6y=22)
5x+30y=110 Eqn 3
Subtracting Eqn 1 from Eqn 3
(5x+30y)-(5x+4y)=110-32
5x+30y-5x+4y=78
26y=78
Dividing both sides by 26
Putting y=3 in Eqn 2
x+6(3)=22
x+18=22
x=22-18
x=4
Hence,
Option a: A rose costs $1 more than a daisy is the correct answer.