Question 787462
Let {{{ g(x) = m*x + b }}}
where {{{ m }}} = slope and {{{ b }}} = intercept at {{{ x = 0 }}}
given:
{{{ g(-1) = m*(-1) + b }}}
(1) {{{ -3 = -m + b }}}
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{{{ g(-4) = m*(-4) + b }}}
(2) {{{ 12 = -4m + b }}}
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Subtract (2) from (1)
(1) {{{ -3 = -m + b }}}
(2) {{{ -12 = 4m - b }}}
{{{ -15 = 3m }}}
{{{ m = -5 }}}
and, since
(1) {{{ -3 = -m + b }}}
(1) {{{ -3 = -(-5) + b }}}
(1) {{{ -3 = 5 + b }}}
(1) {{{ b = -8 }}}
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{{{ g(x) = -5x - 8 }}}
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check:
{{{ g(-4) = -5*(-4) - 8 }}}
{{{ g(-4) = 20 - 8 }}}
{{{ g(-4) = 12 }}}
OK
You can check {{{ g(-1) }}}