Texas Instruments TI-89 Titanium User Manual page 77

equation, and solve for the value of y. Then substitute the y value back into the first
equation to solve for the value of x.
Steps and keystrokes
1. Display the Home screen and clear the
entry line. Solve the equation 2x N 3y = 4
for x.
„
selects
1 solve(
menu. You can also type
from the keyboard or select it from the
.
Catalog
@ " M M „ 1 2 X | 3 Y
Á 4 b X d ¸
2. Begin to solve the equation Lx + 7y = L12
for y, but do not press ¸ yet.
Press „ 1 ? X « 7 Y Á ? 12 b Y d
3. Use the "with" operator to substitute the
expression for x that was calculated from
the first equation. This gives the value of
y.
The "with" operator is displayed as | on
the screen.
Use the auto-paste feature to highlight the
last answer in the history area and paste
it to the entry line.
@ Í C ¸ ¸
Previews
from the Algebra
directly
solve(
Display
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