Answer:
x = -4, 5/2
Step-by-step explanation:
A quadratic can be solved may ways, including graphing, factoring, and the quadratic formula. You can also check possible answers by making use of the relationships between solutions and the coefficients.
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A graph is attached. It shows the solutions to be -4 and 5/2.
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When factored, the equation becomes ...
(2x -5)(x +4) = 0 . . . . . has solutions x=-4, x=5/2 (these make the factors zero)
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Using the quadratic formula, the solutions of ax^2 +bx +c = 0 are found from ...
x = (-b±√(b²-4ac))/(2a)
x = (-3±√(3²-4(2)(-20))/(2(2)) = (-3±√169)/4 = {-16, +10}/4
x = {-4, 5/2}
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For ax^2 +bx +c = 0, the solutions must satisfy ...
product of solutions is c/a = -20/2 = -10
Only the first and last choices have this product.
sum of solutions is -b/a = -3/2
Only the first choice (-4, 5/2) has this sum.
The right answer for the question that is being asked and shown above is that: "13 ft."An iron tank is constructed in the form of an isosceles trapezoid. Each base angle measures 105°, the length of the base is 10 feet, and each of the <span>nonparallel sides is 12 feet long. The length of a diagonal brace to the nearest whole number is 13 ft</span>
The answer is 40°
i will tell you how,
Total angle sum of any triangle is 180°
∠A + ∠B + ∠E = 180°
70° + 80° + ∠E = 180°
solve for ∠E
∠E = 30°
Now solve use ∠BDE,
∠B + ∠D + ∠E = 180°
20° + 90° + 30° + x = 180° (in triangle DEB, ∠E = 30 + x ) (∠D is 90°)
solve for x
there fore, x = 40°