Question:
Brianna solved a two-step equation, but she made a mistake along the way.
[tex]0.1x + 3 = 1.7[/tex]
Line 1
: [tex](-3) + 0.1x + 3 = 1.7 + (-3)[/tex]
Line 2
: [tex]0.1x = -1.3[/tex]
Line 3
: [tex](-0.1) + 0.1x = -1.3 + (-0.1)[/tex]
Line 4: [tex]x = -1.4[/tex]
Answer:
On Line 3, Brianna should have divided by 0.1 instead of subtracting 0.1.
Step-by-step explanation:
Required
Where did she make a mistake?
To do this, we simply analyse her workings one step at a time
Equation: [tex]0.1x + 3 = 1.7[/tex]
Line 1
: [tex](-3) + 0.1x + 3 = 1.7 + (-3)[/tex]
This is correct because she subtracted 0.3 from both sides
Line 2
: [tex]0.1x = -1.3[/tex]
This is also correct because she performed the arithmetic correctly
Line 3
: [tex](-0.1) + 0.1x = -1.3 + (-0.1)[/tex]
This is incorrect.
Division by 0.1 is expected not subtraction
