Answer: x = -0.2651 and y = -0.9759
Step-by-step explanation:
Solution by substitution method
8x+5y= -7
-7x+6y= -4 = 7x-6y=4
Suppose,
8x+5y=-7→(1)
7x-6y=4→(2)
Taking equation (1), we have
8x+5y= -7
⇒8x= -5y -7
⇒x= -5y-7 / 8 →(3)
Putting x= -5y-7 / 8
in equation (2), we get 7x-6y=4
7(-5y-7/8)-6y=4
⇒-35y-49-48y=32
⇒-83y-49=32
⇒-83y=32+49
⇒-83y=81
⇒y= 81 / -83
⇒y= -0.9759→(4)
Now, Putting y= -0.9759 in equation (3), we get
x= -5y-7
x= -5(-0.9759)-7/8
⇒x= 4.8795-7/8
⇒x= -2.1205/8
⇒x= -0.2651
∴x= -0.2651 and y = -0.9759
Lo siento, no hablo español
answer
10
step-by-step explanation
the equation given is sin(x) = cos(y) with x = 2k + 3 and y = 6k + 7
substitute in 2k+ 3 for x in sin(x) and substitute in 6k + 7 for y in cos(y)
sin(x) = cos(y)
sin(2k + 3) = cos(6k + 7)
we know that sin(x) = cos(90 -x)
sin(2k + 3)
= cos(90 - (2k + 3) )
= cos(90 - 2k - 3)
= cos(87 - 2k)
substitute this into the equation sin(2k + 3) = cos(6k + 7)
sin(2k + 3) = cos(6k + 7)
cos(87 - 2k) = cos(6k + 7)
87 - 2k = 6k +7
80 = 8k
k = 10
