In each case, you can use the second equation to create an expression for y that will substitute into the first equation. Then you can write the result in standard form and use any of several means to find the number of solutions.
System A
x² + (-x/2)² = 17
x² = 17/(5/4) = 13.6
x = ±√13.6 . . . . 2 real solutions
System B
-6x +5 = x² -7x +10
x² -x +5 = 0
The discriminant is ...
D = (-1)²-4(1)(5) = -20 . . . . 0 real solutions
System C
y = 8x +17 = -2x² +9
2x² +8x +8 = 0
2(x+2)² = 0
x = -2 . . . . 1 real solution
The correct answers are 6/9 and 4/6
Answer:
21
Step-by-step explanation:
(9g+4)-55=
(72+4)-55=
76-55=
21
Answer:
A. x = 2 and y =2
B. x = 3 and y = -1
Step-by-step explanation:
A. {
x = 3y − 4
2x − y = 2
1) Substitute the value of x
2(3y − 4) − y = 2
2) Solve the equation for y
y = 2
3) Substitute the value of y
x= 3(2) -4
4) Solve the equation for x
x = 2
Final Solution: x = 2 and y =2
B. {
3x + 2y = 7
−x + y = −4
1) Multiply both sides of the equation by 3
-3x + 3y = -12
2) Eliminate one variable by adding the equations
3x + 2y = 7
<u>+ (−3x + 3y = −12)</u>
5y = -5
3) Divide both sides of the equation by 5
y = -1
4) Substitute the given value of y into the equation -x + y = -4
-x + (-1) = -4
5) Solve the equation for x
x = 3
Final Solution: x = 3 and y = -1
