using the method of elimination by addition and subtraction. Notice that if we multiply all terms of the first equation by 3 and all terms of the second by 4, y as a variable will temporarily disappear:
9x + 12y = 15
8x - 12y = -32
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17x = - 17, so x = -1.
Replacing x in the second equation by -1, we get:
2(-1) - 3y = -8, or
2 + 3y = 8,
or 3y = 6. Thus, y = 2, and the solution is (-1, 2).
A1=8 common ratio=r sum of 6 terms S=a1+a2+a3+...+a6 =a1(1+r+r^2+...+r^5) =a1(r^6-1)/(r-1) but we're given S=74648 => 8(r^6-1)/(r-1)=74648 Cross multiply and solve for r (by trial and error) r^6-1=9331(r-1) r=6 so a(3)=a1*r^(3-1) =8*(6^2) =288