Compare two variables each time
First, let's multiply the first equation by two on the both sides:
<span>8x + 7y = 39 /2
</span>⇒ 16x + 14y = 78
Now, the system is:
<span>16x + 14y = 78
</span><span>4x – 14y = –68
</span>
After adding this up in the column:
(16x + 4x) + (14y - 14y) = 78 - 68
20x = 10
⇒ x = 10/20 = 1/2
y can be calculated by replacin the x:
<span>8x + 7y = 39
</span>⇒ 8 · 1/2 + 7y = 39
4 + 7y = 39
7y = 39 - 4
7y = 35
⇒ y = 35 ÷ 7 = 5
Answer:
10*40
80*5
20*20
Step-by-step explanation:
20*20=400
80*5=400
10*40=400
Answer:
C
Step-by-step explanation:
y = 2x + 5
the slope (m) of this line is 2 (which can be written as 2/1)
The slope of a perpendicular line is -1/m (the reciprocal of the slope with the opposite sign)
so m = 2/1 => -1/m = - 1/2 = the slope of a line perpendicular to y = 2x + 5
Answer:
false
Step-by-step explanation:
false , because A is between C and B , it must be on the same straight line
