Recall the formula to find the solutions for an equation ax² + bx + c:
x₁₂ = (- b +/- √(b²-4ac) )/ 2a
Since at the denominator of our solution we have 3, which is an odd number, therefore it cannot be 2a, but only a, we should use the formula:
x₁₂ = <span>(-β +/- √(β²-ac) )/ a
Where </span>β = b/2
Hence, the only options that have an even number as b coefficient are C and D.
Now, we need to find what values give √(β² - ac) = 2√7 = √(4·7) = √28:
C) √(β² - ac) = √(25 - 3·6) = √7
D) √(β² - ac) = <span>√(25 - 3·(-1))</span> = √28
Hence, the correct answer is D) 3x² - 10x - 1 = 0
7 is 71+7/3+78
8 is 60x2x2
Answer:
$77.18
Step-by-step explanation:
A = total amount
P = principal
I = interest
A = P(1 + r/n)^n·t
A = 70(1+.05)²
A = 70(1.05)²
A = 77.175
I = A - P
Answer:
6450
Step-by-step explanation:
1kg = 1000g
6.45 x 1000 = 6450
