Question

What is the answer to 7(x-1)<9x+1?

Answer 1

$7(x-1) < 9x+1$

$7x-7 < 9x+1$

$-7 < 2x+1$

$-8 < 2x$

$-4 < x$

$\boxed{x>-4}$

Answer 2

$7(x-1) < 9x+1\\7(x)+7(-1) <9x+1\\7x-7 < 9x+1\ \ \ \ |add\ 7\ to\ both\ sides\\7x < 9x + 8\ \ \ \ |subtract\ 9x\ from\ both\ sides\\-2x < 8\\2x > -8\ \ \ \ \ |divide\ both\ sides\ by\ 2\\\boxed{x > -4\Rightarrow x\in(-4;\ \infty)}$