Answer:
1)x=3
2)t=-4
Step-by-step explanation:
x-9=-12
x=3
2t=-8
t=-4
Answer:
2x^2 = 6x - 5.
-x^2 - 10x = 34.
These have only complex roots/
Step-by-step explanation:
3x^2 - 5x = -8
3x^2 - 5x + 8 = 0
There are complex roots if the discriminant 9b^2 - 4ac) is negative.
Here the discriminant D = (-5)^2 - 4*-5*8 = 25 + 160
This is positive so the roots are real.
2x^2 = 6x - 5
2x^2 - 6x + 5 = 0
D = (-6)^2 - 4*2*5 = 36 - 40 = -4
So this has no real roots only complex ones.
12x = 9x^2 + 4
9x^2 - 12x + 4 = 0
D = (-12)^2 - 4*9 * 4 = 144 - 144 = 0.
- Real roots.
-x^2 - 10x = 34
x^2 + 10x + 34 = 0
D = (10)^2 - 4*1*34 = 100 - 136 = -36.
No real roots = only complex roots.
Answer:
See below.
Step-by-step explanation:
a.
The first figure has 1 square. The second figure has a column of 2 squares added to the left. The third figure has a column of 3 squares added to the left. Each new figure has a column of squares added to the left containing the same number of squares as the number of the figure.
b.
Figure 10 has 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10 = 55 squares.
c.
The formula for adding n positive integers starting at 1 is:
1 + 2 + 3 + ... + n = n(n + 1)/2
For figure 55, n = 55.
n(n + 1)/2 = 55(56)/2 = 1540
d.
Let's use the formula set equal to 190 and solve for n. If n is an integer, then we can.
n(n + 1)/2 = 190
n(n + 1) = 380
We know that 380 = 19 * 20, so n = 19.
Answer: yes
e.
Use the formula above,
S = n(n + 1)/2, where S is the sum.
f.
n(n + 1) = 1478
38 * 39 = 1482
37 * 38 = 1406
