x represents the number of home runs lu hit
so, the number of home runs for Karinne = 0.5 * x + 4
together, they hit 10 home runs
so,
x + 0.5 * x + 4 = 10
solve for x
so,
1.5 * x = 10 - 4
1.5 * x = 6
divide both sides by 1.5
so,
x = 6/1.5 = 4
So,
The number of home runs Lu hit = 4
And the number of home runs Karinne hit = 6