X + y + z = 2
x - y + 5z = 6
cancelando +y com -y:
x + z = 2*(-5)
x + 5z = 6
-5x -5z = -10
...x +5z = 6
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-4x = -4 *(-1)
4x = 4
x = 4/4
x = 1
x + z = 2
1 + z = 2
z = 2 - 1
z = 1
x + y + z = 2
1 + y + 1 = 2
2 + y = 2
y = 2 - 2
y = 0
S: {x, y, z} = {1, 0, 1}
= > x² + 7x + 12 = 12
= > x² + ( 4 + 3 )x + 12 = 12
= > x² + 4x + 3x + 12 = 12
= > x( x + 4 ) + 3( x + 4 ) = 12
= > ( x + 4 ) ( x + 3 ) = 12
Percy did correct till this step. But by doing like this, Percy can't get the values of the variable x.
Percy should follow the following steps :
= > x² + 7x + 12 = 12
Add -12 on both sides,
= > x² + 7x + 12 - 12 = 12 - 12
= > x² + 7x = 0
= > x( x + 7 ) = 0
= > ( x = 0 ) or ( x + 7 = 0 )
= > ( x = 0 ) or ( x = - 7 )
Hence, required value(s) of x is 0 or -7
Answer:
(-3,7)
Step-by-step explanation:
Answer:
Width: 10 inches
Length: 15 inches
Step-by-step explanation:
Let the width be w.
Since the length is 5 inches longer than its width, the length = w +5.
Area of rectangle = length x width
w (w +5) = 150
w^2 + 5w = 150
w^2 + 5w -150 = 0
Using quadratic formula,
w = 10 or -15
Since the width cannot be negative,
the width is 10 inches.
Now just substitute w=10 into length = w +5.
length = 10 + 5
= 15 inches
Answer:
d = 1
Step-by-step explanation:
5(d+2)=15 (Given)
5d + 10 = 15 (distribute)
5d = 5 (subtraction)
d = 1 (division)