Answer:
x = -2 and y = 3
Step-by-step explanation:
It is given that,
4x + 5y = 7 -----(1)
3x – 2y = –12 ----(2)
<u>To find the value of x and y</u>
eq(1) * 3 ⇒
12x + 15y = 21 ----(3)
eq(2) * 4 ⇒
12x - 8y = -48 ---(4)
eq(3) - eq(4) ⇒
12x + 15y = 21 ----(3)
<u>12x - 8y = -48 </u> ---(4)
0 + 23y = 69
y = 69/23 = 3
Substitute the value of y in eq(1)
4x + 5y = 7 ----(1)
4x + 5*3 = 7
4x = 7 - 15 = -8
x = -8/4 = -2
Therefore x = -2 and y = 3
Answer: It is B
Rae will ask 75 randomb students in her school
Step-by-step explanation:
honestly I just guessed, and got it right
Step-by-step explanation:
charging the phone for 1 minute ,it has 2%
i.e,1----->2
After 2 minutes from that time ,i.e total 3 minutes
it has 6% charge
i.e,3--------->6
from the both the above cases ,1 minute provide 2%=6/3
=2
Hence,
for getting 50%charge=50/2
=25 min
and,for 90 %charge=90\2
=45 min
Answer:
B
Hope this Helps! Have A Nice Day!!
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Answer:
(a) x = (3 -ln(3))/5 ≈ 0.819722457734
(b) y = 10
Step-by-step explanation:
(a) Taking the natural log of both sides, we have ...
2x +1 = ln(3) +4 -3x
5x = ln(3) +3 . . . . . . . . add 3x-1
x = (ln(3) +3)/5 ≈ 0.820
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(b) Assuming "lg" means "log", the logarithm to base 10, we have ...
log(y -6) +log(y +15) = 2
(y -6)(y +15) = 100 . . . . . . . taking antilogs
y^2 -9x -190 = 0 . . . . . . . . eliminate parentheses, subtract 100
(y -19)(y +10) = 0 . . . . . . . . factor
The values of y that make these factors zero are -19 and 10. We know from the first term that (y-6) > 0, so y > 6. That means y = -19 is an extraneous solution.
The solution is ...
y = 10
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When solving equations using a graphing calculator, it often works well to define a function f(x) such that the solution is f(x) = 0, the x-intercept(s). That form is easily obtained by subtracting the right side of the equation from both sides of the equation. In part (a) here, that is ...
f(x) = e^(2x+1) -3e^(4-3x)