First, expand the expression on the left side of the equation:
2x(8−7x)=16x−14x2. Now the equation is 16x−14x2=−11. Rearrange the equation to the standard quadratic form ax2+bx+c=0: −14x2+16x+11=0. Multiply by −1 to make the leading coefficient positive: 14x2−16x−11=0. Now, we use the quadratic formula to solve for x: x=2a−b±b2−4ac In this case, a=14, b=−16, and c=−11. Plugging these values into the quadratic formula:
x=2(14)−(−16)±(−16)2−4(14)(−11) x=2816±256+616 x=2816±872 x=2816±2218 x=148±218 Now we find the two possible values of x: x1=148+218≈148+14.76≈1422.76≈1.6257≈1.63 (to 2 decimal places) x2=148−218≈148−14.76≈14−6.76≈−0.4829≈−0.48 (to 2 decimal places)