Solve using the quadratic formula.8r2+5r−7=0Write your answers as integers, proper or improper fractions in simplest form, or decimals rounded to the nearest hundredth.r=_____ or r=_____
Q. Solve using the quadratic formula.8r2+5r−7=0Write your answers as integers, proper or improper fractions in simplest form, or decimals rounded to the nearest hundredth.r=_____ or r=_____
Identify Coefficients: To solve the quadratic equation8r2+5r−7=0 using the quadratic formula, we first identify the coefficients a, b, and c from the standard form of a quadratic equation ax2+bx+c=0. Here, a=8, b=5, and c=−7.
Apply Quadratic Formula: The quadratic formula is given by r=2a−b±b2−4ac. We will substitute the values of a, b, and c into this formula to find the solutions for r.
Calculate Discriminant: First, calculate the discriminant, which is the part under the square root in the quadratic formula: b2−4ac. This is 52−4(8)(−7)=25+224=249.
Plug Values into Formula: Now, we can plug the values into the quadratic formula: r=16−5±249. Since 249 is not a perfect square, we will leave the square root as is for now.
Find Solutions: We have two possible solutions for r, corresponding to the '±' in the formula. The first solution is r=16−5+249, and the second solution is r=16−5−249.
Simplify Solutions: To simplify the solutions, we can leave them in the form of fractions or approximate them as decimals. The square root of 249 cannot be simplified further, so we will leave it as 249. The fraction cannot be simplified further either, so the solutions in fraction form are r=16−5+249 and r=16−5−249.
Approximate Decimal Solutions: If we want to express the solutions as decimals, we can use a calculator to approximate 249 and then divide by 16. The approximate values are r≈(−5+15.78)/16≈0.67 and r≈(−5−15.78)/16≈−1.30, rounded to the nearest hundredth.
More problems from Solve a quadratic equation using the quadratic formula