Answer: 
Step-by-step explanation:
To find the least common multiply, you must descompose 12 and 15 into their prime factors, as you can see below:
12=2*2*3=2²*3
15=3*5
Choose the common and non common numbers with their greastest exponents:
3*5*2²=60
Now you must choose the common and non common variables with their greastest exponents:
n³
Therefore, you can conclude that the least common multiply is:

Step-by-step explanation:
- 3x+5y=7b equation 1
- 2x+4y=1
2x=-4y+1
- x=(-4y+1)/2
- x=(-4y+1)/2 in equation 1
3×(-4y+1)/2+5y=7b
(-12y+3)/2+5y=7b
(-12y+3+10y)/2=7b
(-12y+3)/2=7b
-12y+3=14b
-12y=14b-3
- y=3-14b/12
- y=3-14b/12 in x=(-4y+1)/2
x=(-4×{3-14b/12}+1)/2
x=(-3+14b)/3+1/2
x=14b/3×1/2
Sorry don't know the answer