SOLUTION: I'm 46 years old and working on refreshing my skills. How do I solve this using the substitution method? 12a-5b=18 ...(1) 15a-5b=30 ... (2) from eq(2) b=3a-6 substitut

Algebra ->  Graphs -> SOLUTION: I'm 46 years old and working on refreshing my skills. How do I solve this using the substitution method? 12a-5b=18 ...(1) 15a-5b=30 ... (2) from eq(2) b=3a-6 substitut      Log On


   



Question 459614: I'm 46 years old and working on refreshing my skills. How do I solve this using the substitution method?
12a-5b=18 ...(1)
15a-5b=30 ... (2)
from eq(2)
b=3a-6
substituting the value of b in eq(1)
12a-5(3a-6)=18
12a-15a+30=18
-3a=-12
a=4
hence b=3a-6=6
Thanks

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