Find the zeros of polynomial functions and solve polynomials equations. f(x)=x^2+3x-18

When you have a quadratic equation in this form, i.e. with the x^2 coefficient set to one, you can find its solution with a little shortcut.

Instead of using the quadratic formula, you can find the solutions like this: if you read the equation as

then is the sum of the solutions, and is their product.

Since has a minus sign in front of it, the sum of the solutions must be -3. Also, their product has to be -18.

Since the product is negative, the two numbers have opposite sign. Since the sum is also negative, the biggest number (in absolute value) is the negative one.

You can have 18 as a product by choosing 1 and -18, 2 and -9 or 3 and -6.

This last couple sum to -3, so the two solutions are 3 and -6

26 is 33.33% of 78

step-by-step explanation:

26 is what percent of 78?

26 is p% of 78

equation: y = p% * x

solving our equation for p

p% = y/x

p% = 26/78

p = 0.3333

convert decimal to percent:

p% = 0.3333 * 100 = 33.33%