1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
antoniya [11.8K]
3 years ago
7

For what value of a does the equation ax^2−3x−5=0 have 1 as one of its roots?

Mathematics
1 answer:
tester [92]3 years ago
6 0
First, rearrange the equation so you have just ax² on one side. This can be done by adding -3x and -5 on both sides of the equation:
ax²=3x+5
Now, substitute x for 1 and simplify:
a(1²)=(3×1)+5
1a=3+5
a=8
You can double check this by substituting a for 8 back into the original equation:
(8×1²)-(3×1)-5=0
8-3-5=0
You might be interested in
Given: sin ∅= 4/5 and cos x = -5/13 ; evaluate the following expression.<br><br> tan( ∅ - x )
Pavlova-9 [17]

By definition of tangent,

tan(θ - x) = sin(θ - x) / cos(θ - x)

Expand the sine and cosine terms using the angle sum identities,

sin(x ± y) = sin(x) cos(y) ± cos(x) sin(y)

cos(x ± y) = cos(x) cos(y) ∓ sin(x) sin(y)

from which we get

tan(θ - x) = (sin(θ) cos(x) - cos(θ) sin(x)) / (cos(θ) cos(x) + sin(θ) sin(x))

Also recall the Pythagorean identity,

cos²(x) + sin²(x) = 1

from which we have two possible values for each of cos(θ) and sin(x):

cos(θ) = ± √(1 - sin²(θ)) = ± 3/5

sin(x) = ± √(1 - cos²(x)) = ± 12/13

Since there are 2 choices each for cos(θ) and sin(x), we'll have 4 possible values of tan(θ - x) :

• cos(θ) = 3/5, sin(x) = 12/13 :

tan(θ - x) = -56/33

• cos(θ) = -3/5, sin(x) = 12/13 :

tan(θ - x) = 16/63

• cos(θ) = 3/5, sin(x) = -12/13 :

tan(θ - x) = -16/63

• cos(θ) = -3/5, sin(x) = -12/13 :

tan(θ - x) = 56/33

7 0
2 years ago
Read 2 more answers
7 <br><br><br>Find the value of the expression. Z + 2y for y = 6 and z = 1​
Volgvan

Answer:

13

Step-by-step explanation:

1+2×6=13

boy!!!!!!!!!!!!!!

8 0
3 years ago
I really need help. I dont understand.
mash [69]
Y=-x-8
the y-intercept is 8, while the slope is 1
8 0
4 years ago
Read 2 more answers
Compute each sum or difference<br> 9/10+7/9<br> 1/2-3/11<br> 2/5-1/15
Galina-37 [17]
1. 9/10 + 7/9 = 81/90 + 70/90 = 151/90 = 1 61/90
2. 1/2-3/11 = 11/22-6/22 = 5/22
3. 2/5-1/15 = 6/15-1/15 = 5/15 =1/3
8 0
3 years ago
Read 2 more answers
A school holds classes from 8:00 A.M to 2:00 P.M. For what percent of 24-hour day does this school hold classes?
lesya [120]

Answer:

25%

Step-by-step explanation:

So first we need to find out how many hours the school has class. Its 4 hours from 8 to noon, then another 2 from noon to 2. This means the school has class 6 hours a day.

Now we need to figure out the percent. we need to have hours of school over total hours or 6/24

6/24

we can simplify this by dividing both sides by 6

(6/6)/(24/6)=1/4

1/4 is 25%

The school holds class for 25% of the day

5 0
3 years ago
Read 2 more answers
Other questions:
  • In order to paint your bedroom, you buy 2 gallons of paint that cost $10.50 each, 3 paint brushes that cost $2.99 each, and 2 pa
    10·1 answer
  • If the bird is directly above the fish, how far apart are they
    15·1 answer
  • Given the function defined below, what is the value of the 4th term?
    11·1 answer
  • How do you write an equation with (7,7) and (-3,7)
    15·1 answer
  • Hi can any one please help me i need help in this please
    11·1 answer
  • What is another way to write 3 x (4 +7)?
    5·1 answer
  • FIND THE VALUE OF X.<br> GIVEN ABCDEF~JKLMNP.
    8·1 answer
  • On each trial of a digit span memory task, the participant is asked to read aloud a string of random digits. The participant mus
    14·1 answer
  • Explanation please will give brainliest.​
    7·1 answer
  • Solve the proportion: 144/a = 9/4<br>a=?<br>​
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!