The best approximation for the solution to this system of equations is (-2.2,-3)
Option C is correct.
Step-by-step explanation:
Solving the system of equations to get the exact value of x:
Let
Putting value of y from eq(1) into eq(2)
So, Value of x is -2.2
The best approximation for the solution to this system of equations is:
x=-2.2 and y = -3
(-2.2,-3)
Option C is correct.
Keywords: System of equations
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Answer:
b. (1, 3, -2)
Step-by-step explanation:
A graphing calculator or scientific calculator can solve this system of equations for you, or you can use any of the usual methods: elimination, substitution, matrix methods, Cramer's rule.
It can also work well to try the offered choices in the given equations. Sometimes, it can work best to choose an equation other than the first one for this. The last equation here seems a good one for eliminating bad answers:
a: -1 -5(1) +2(-4) = -14 ≠ -18
b: 1 -5(3) +2(-2) = -18 . . . . potential choice
c: 3 -5(8) +2(1) = -35 ≠ -18
d: 2 -5(-3) +2(0) = 17 ≠ -18
This shows choice B as the only viable option. Further checking can be done to make sure that solution works in the other equations:
2(1) +(3) -3(-2) = 11 . . . . choice B works in equation 1
-(1) +2(3) +4(-2) = -3 . . . choice B works in equation 2
(5x+1)² = 7; expand: 25x² + 10x +1 = 7 or 25x² + 10x -6 = 0
Solve this quadratic for x:
x = [-b + √(b² - 4ac)]/2a and x = [-b - √(b² - 4ac)]/2a
Plug the values and you'll find :
x = (- √7 - 1)/5 (answer C)
x = (+√7 -1)/5 (answer E)
