Question
Solve the quadratic equation
Solve using the quadratic formula
Solve by completing the square
Solve using the PQ formula
y1=39−46,y2=39+46
Alternative Form
y1≈−0.265986,y2≈6.265986
Evaluate
3y2−18y−5=0
Substitute a=3,b=−18 and c=−5 into the quadratic formula y=2a−b±b2−4ac
y=2×318±(−18)2−4×3(−5)
Simplify the expression
y=618±(−18)2−4×3(−5)
Simplify the expression
More Steps

Evaluate
(−18)2−4×3(−5)
Multiply
More Steps

Multiply the terms
4×3(−5)
Rewrite the expression
−4×3×5
Multiply the terms
−60
(−18)2−(−60)
Rewrite the expression
182−(−60)
If a negative sign or a subtraction symbol appears outside parentheses, remove the parentheses and change the sign of every term within the parentheses
182+60
Evaluate the power
324+60
Add the numbers
384
y=618±384
Simplify the radical expression
More Steps

Evaluate
384
Write the expression as a product where the root of one of the factors can be evaluated
64×6
Write the number in exponential form with the base of 8
82×6
The root of a product is equal to the product of the roots of each factor
82×6
Reduce the index of the radical and exponent with 2
86
y=618±86
Separate the equation into 2 possible cases
y=618+86y=618−86
Simplify the expression
More Steps

Evaluate
y=618+86
Divide the terms
More Steps

Evaluate
618+86
Rewrite the expression
62(9+46)
Cancel out the common factor 2
39+46
y=39+46
y=39+46y=618−86
Simplify the expression
More Steps

Evaluate
y=618−86
Divide the terms
More Steps

Evaluate
618−86
Rewrite the expression
62(9−46)
Cancel out the common factor 2
39−46
y=39−46
y=39+46y=39−46
Solution
y1=39−46,y2=39+46
Alternative Form
y1≈−0.265986,y2≈6.265986
Show Solution
