Solve the following system using elimination:
{7 x + 2 y = -19 | (equation 1)
{2 y - x = 21 | (equation 2)
Add 1/7 × (equation 1) to equation 2:
{7 x + 2 y = -19 | (equation 1)
{0 x+(16 y)/7 = 128/7 | (equation 2)
Multiply equation 2 by 7/16:
{7 x + 2 y = -19 | (equation 1)
{0 x+y = 8 | (equation 2)
Subtract 2 × (equation 2) from equation 1:
{7 x+0 y = -35 | (equation 1)
{0 x+y = 8 | (equation 2)
Divide equation 1 by 7:
{x+0 y = -5 | (equation 1)
{0 x+y = 8 | (equation 2)
Collect results:
Answer: {x = -5, y = 8
20 * 15 * 10 *10^-6
= 0.003
Answer:
SAS
Step-by-step explanation:
Answer: x = (sqrt(7) + 2)/3 and
x = ( – sqrt(7) + 2)/3
Explanation:
3x^2 - 4x - 1 = 0
Divide both sides by 3:
3x^2/3 - 4/3x - 1/3 = 0/3
x^2 - 4/3x - 1/3 = 0
x^2 - 4/3x = 1/3
x^2 - 4/3x + (2/3)^2 = 1/3 + (2/3)^2
(x - 2/3)^2 = 1/3 + 4/9
(x - 2/3)^2 = 7/9
Sqrt both sides:
x - 2/3 = sqrt (7/9)
x - 2/3 = |sqrt(7)/3|
Set x -2/3 = sqrt(7)/3
=> x = (sqrt(7) + 2)/3
Set x - 2/3 = - sqrt(7)/3
=> x = ( - sqrt(7) + 2)/3
