Question

the graph of linear function k has slope -4 and passes through (1,8). what is the zero in function k? ​

Answer 1

Answer:

$x=3$

Step-by-step explanation:

Let $k(x)=mx+b$ be the expression for the linear function k(x), where m is the slope of the function and this function passes through the point (1,8).

Thus, $m=-4$ and the function expression is

$k(x)=-4x+b$

If the graph of the function passes through the point (1,8), then its coordinates satisfy the function expression. Substitute them:

$8=-4\cdot 1+b\\ \\8=-4+b\\ \\b=8-(-4)\\ \\b=12$

Hence,

$k(x)=-4x+12$

The graph of this function intersects the x-axis at k(x)=0, then

$-4x+12=0\\ \\-4x=-12\\ \\x=3$

Zero of the function is x=3