Use the elimination method.
(-5x + y = 26)7
2x - 7y = 16
-35x + 7y = 182
2x - 7y = 16
-33x = 198
x = -6
Substitiute -6 for x in one of the equations.
2x -7y = 16
2(-6) - 7y = 16
-12 - 7y =16
-7y = 28
y = -4
The ordered pair would be (-6,-4)
The first four terms are -6, -7, -9 and -13.
Step-by-step explanation:
- Step 1: Given first term, a(1) = -6 and the nth term, a(n) = 2a(n-1) + 5. FInd the first four terms.
⇒ a(1) = -6
⇒ a(2) = 2a(1) + 5 = 2 × -6 + 5 = -12 + 5 = -7
⇒ a(3) = 2a(2) + 5 = 2 × -7 + 5 = -14 + 5 = -9
⇒ a(4) = 2a(3) + 5 = 2 × -9 + 5 = -18 + 5 = -13
The <u>correct answers</u> are:
#1) Open; there is a variable;
#2) Yes;
#3) No;
#4) (-10, -30); and
#5) (10, -86).
Explanation:
#1) An open sentence is one that contains a variable. This has a variable, p, on each side, so it is an open sentence.
#2) Solving the equation
2 - 8x = -6
Subtract 2 from each side:
2 - 8x - 2 = -6 - 2
-8x = -8
Divide both sides by -8:
-8x/-8 = -8/-8
x = 1
The answer is yes.
#3) For the equation y = 4x, to see if (3, 13) is a solution, substitute 3 for x:
y = 4(3)
y = 12
Since it is not 13, (3, 13) is not a solution.
#4) For the equation y = 3x, if we substitute -10 for x, we have:
y = 3(-10) = -30
The solution would be (-10, -30).
#5) For the equation y = -9x + 4, substitute 10 for x:
y = -9(10) + 4
y = -90 + 4
y = -86
The solution would be (10, -86).