12 because you said 8+4 and it equal to 12 that how I got my answer or you can draw a model to.
3.9 x 5.1 = 19.89
10^3 x 10^3 = 10^6
19.89 x 10^6
move decimal point
1.989 x 10^7
Answer:
x - intercept: -1.2
y - intercept: -0.7