Answer:
Determine whether each of the following is a solution of x − 0.7 = 1.5: (a) x = 1 (b) x = −0.8 (c) x = 2.2
Solution
(a) x - 0.7 = 1.5
Substitute 1
1
for x.
1−0.7=?1.5(5.7.1)
(5.7.1)
1
−0.7
=
?
1.5
Subtract.
0.3≠1.5(5.7.2)
(5.7.2) 0.3≠1.5
Since x = 1 does not result in a true equation, 1 is not a solution to the equation.
(b) x - 0.7 = 1.5
Substitute −0.8
−
0.8
for x.
−0.8−0.7=?1.5(5.7.3)
(5.7.3)
−
0.8
−0.7
=
?
1.5
Subtract.
−1.5≠1.5(5.7.4)
(5.7.4) −1.5≠1.5
Since x = −0.8 does not result in a true equation, −0.8 is not a solution to the equation.
(c) x - 0.7 = 1.5
Substitute 2.2
2.2
for x.
2.2−0.7=?1.5(5.7.5)
(5.7.5)
2.2
−0.7
=
?
1.5
Subtract.
1.5=1.5✓(5.7.6)
(5.7.6) 1.5=1.5✓
Since x = 2.2 results in a true equation, 2.2 is a solution to the equation.
Step-by-step explanation:
More ... The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol.
