Answer:
4.1
Step-by-step explanation:
X+ 7.8 = 11.9
X= 11.9 - 7.8
X= 4.1
x = 4.1
To solve for x, subtract 7.8 from both sides of x + 7.8 = 11.9:
x + 7.8 - 7.8 = 11.9 - 7.8, or