Answer:
1. x² + 3x - 5 = 0
2. x² - x = 3 x + 7
4. 7x² + 14x = 0
Step-by-step explanation:
A Quadratic equation takes the form;
ax² + bx + c = 0
a, b, c are constants and a cannot be 0.
Options 1 fits this;
x² + 3x - 5 = 0
Option 2 fits this as well;
x² - x = 3 x + 7
x² -x - 3x - 7 = 0
x² - 4x - 7 = 0
Option 4 fits this as well if c = 0.
7x² + 14x + 0 = 0
Answer:
10
Step-by-step explanation:
(x + 2) + (-2 + x) = 20
2x + 0 = 20
2x = 20
x = 20/2
x = 10
5 -> 15
6 -> 20
7 -> 25
8 -> 30
9 -> 35
10 -> 40
then in ones:
after 41 would be 42 and 43
the elapsed time would be 43 minutes :)
hope this helps :)
Answer:
0.38268343
Step-by-step explanation:
cos(
67.5
)
Rewrite
67.5
as an angle where the values of the six trigonometric functions are known divided by 2
.
cos
(
135\
2)
Apply the cosine half-angle identity.
±
√
1
+
cos
(
135
)
2
Change the
±
to
+
because cosine is positive in the first quadrant.
√
1
+
cos
(
135
)
2
Simplify
√
1
+
cos
(
135
)
2
√
2
−
√
2
2
The result can be shown in multiple forms.
Exact Form:
√
2
−
√
2
2
Decimal Form:
0.38268343
…
