A quadratic equation is one in which the highest exponent of x is 2.

is quadratic; the highest exponent is 2.
x³-3x²+1=0 is NOT quadratic. The highest exponent of x is 3, not 2.
5x-7=0 is NOT quadratic. The highest exponent of x is 1, not 2.
x²+3x-5=0 is quadratic; the highest exponent of x is 2.
x-5=9x+7 is NOT quadratic. The highest exponent of x is 1, not 2.
x²-x=3x+7 is quadratic; the highest exponent of x is 2.
Answer:
Step-by-step explanation:
Area of square = area of triangle
![side*side = \dfrac{1}{2}b*h\\\\\\x*x=\dfrac{1}{2}*(x+1)(x+2)\\x^{2}=\dfrac{1}{2}[x*x +x*2+1*x+1*2]\\\\\\x^{2}=\dfrac{1}{2}[x^{2}+2x+x+2]\\\\\\x^{2}=\dfrac{1}{2}[x^{2}+3x+2]\\\\\\Multiply \ both \ sides \ by \ 2\\\\2x^{2}=x^{2}+3x+2\\\\2x^{2}-x^{2}-3x-2 = 0](https://tex.z-dn.net/?f=side%2Aside%20%3D%20%5Cdfrac%7B1%7D%7B2%7Db%2Ah%5C%5C%5C%5C%5C%5Cx%2Ax%3D%5Cdfrac%7B1%7D%7B2%7D%2A%28x%2B1%29%28x%2B2%29%5C%5Cx%5E%7B2%7D%3D%5Cdfrac%7B1%7D%7B2%7D%5Bx%2Ax%20%2Bx%2A2%2B1%2Ax%2B1%2A2%5D%5C%5C%5C%5C%5C%5Cx%5E%7B2%7D%3D%5Cdfrac%7B1%7D%7B2%7D%5Bx%5E%7B2%7D%2B2x%2Bx%2B2%5D%5C%5C%5C%5C%5C%5Cx%5E%7B2%7D%3D%5Cdfrac%7B1%7D%7B2%7D%5Bx%5E%7B2%7D%2B3x%2B2%5D%5C%5C%5C%5C%5C%5CMultiply%20%5C%20both%20%5C%20sides%20%5C%20by%20%5C%202%5C%5C%5C%5C2x%5E%7B2%7D%3Dx%5E%7B2%7D%2B3x%2B2%5C%5C%5C%5C2x%5E%7B2%7D-x%5E%7B2%7D-3x-2%20%3D%200)
x² - 3x - 2 = 0
Answer:
168 seconds
I edited the answer.
Step-by-step explanation:
To find the the time taken for both lights to flash at the same time, we need to find the lowest common multiple of 28 and 24.
28 x 6 = 168, 24 x 7 = 168
The LCM of 28 and 24 is 168.
So it takes 168 seconds for both lights to flash at the same time.
Answer:
5
Step-by-step explanation:
2x5x7=70