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How many solutions are there for the equation 7x^2-9x=3

User PatchyFog
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1 Answer

4 votes

Answer:

2

Explanation:

For this equation, you want to work out the discriminant (Δ), which is equal to b²-4ac. If Δ>0, there are 2 solutions, if Δ=0, there is one solution, and if Δ<0, there are no solutions. This can be explained with the quadratic formula.

For this problem, you want to convert the question into ax²+bx+c=0 formula.

This makes the question 7x²-9x-3. a here is 7, b is -9, and c is -3.

Substituting these values into the discriminant formula gives (-9)²-4(7×-3), which can be simplified to 81-4×-21, or 81+84. This equals 165 which is > 0, so there are 2 answers.

**This involves using discriminants and the quadratic formula, which you may wish to revise. I'm always happy to help!

User AHJeebon
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